Response of Colorado River runoff to dust radiative forcing in snow

The waters of the Colorado River serve 27 million people in seven states and two countries but are overallocated by more than 10% of the river’s historical mean. Climate models project runoff losses of 7–20% from the basin in this century due to human-induced climate change. Recent work has shown however that by the late 1800s, decades prior to allocation of the river’s runoff in the 1920s, a fivefold increase in dust loading from anthropogenically disturbed soils in the southwest United States was already decreasing snow albedo and shortening the duration of snow cover by several weeks. The degree to which this increase in radiative forcing by dust in snow has affected timing and magnitude of runoff from the Upper Colorado River Basin (UCRB) is unknown. Here we use the Variable Infiltration Capacity model with postdisturbance and predisturbance impacts of dust on albedo to estimate the impact on runoff from the UCRB across 1916–2003. We find that peak runoff at Lees Ferry, Arizona has occurred on average 3 wk earlier under heavier dust loading and that increases in evapotranspiration from earlier exposure of vegetation and soils decreases annual runoff by more than 1.0 billion cubic meters or ∼5% of the annual average. The potential to reduce dust loading through surface stabilization in the deserts and restore more persistent snow cover, slow runoff, and increase water resources in the UCRB may represent an important mitigation opportunity to reduce system management tensions and regional impacts of climate change.     

Plant species richness at archaeological sites suggests ecological legacy of Indigenous subsistence on the Colorado Plateau

Humans have both intentional and unintentional impacts on their environment, yet identifying the enduring ecological legacies of past small-scale societies remains difficult, and as such, evidence is sparse. The present study found evidence of an ecological legacy that persists today within an semiarid ecosystem of western North America. Specifically, the richness of ethnographically important plant species is strongly associated with archaeological complexity and ecological diversity at Puebloan sites in a region known as Bears Ears on the Colorado Plateau. A multivariate model including both environmental and archaeological predictors explains 88% of the variation in ethnographic species richness (ESR), with growing degree days and archaeological site complexity having the strongest effects. At least 31 plant species important to five tribal groups (Navajo, Hopi, Zuni, Ute Mountain Ute, and Apache), including the Four Corners potato (Solanum jamesii), goosefoot (Chenopodium sp.), wolfberry (Lycium pallidum), and sumac (Rhus trilobata), occurred at archaeological sites, despite being uncommon across the wider landscape. Our results reveal a clear ecological legacy of past human behavior: even when holding environmental variables constant, ESR increases significantly as a function of past investment in habitation and subsistence. Consequently, we suggest that propagules of some species were transported and cultivated, intentionally or not, establishing populations that persist to this day. Ensuring persistence will require tribal input for conserving and restoring archaeo-ecosystems containing “high-priority” plant species, especially those held sacred as lifeway medicines. This transdisciplinary approach has important implications for resource management planning, especially in areas such as Bears Ears that will experience greater visitation and associated impacts in the near future.

Local resource abundance is important for determining where in a given landscape humans decide to live. Nearby water, game, soil, and plants provide readily available wild resources for foraging and conditions that allow for cultivation (1–5). However, humans also modify their surrounding environments in order to increase the abundance and diversity of local plant (6–11) and animal (12–15) resources. Such “human niche construction” is a hallmark of ancient and modern societies (16, 17), having positive and negative impacts on global biodiversity while possibly creating enduring ecological legacies (18–21). This may be especially true for more sedentary and dense populations (22, 4) that are more likely to find investment worthwhile (23) and to produce unintentional impacts. Thus, variation in contemporary ecological diversity may in part reflect past land use dynamics and, therefore, be revealed through coupled archaeological and ecological research (24–33).Coupled ecological and archaeological research has led to the discovery of altered patterns of succession resulting from 1) forest clearing and changes in canopy light regime (34, 35), 2) alterations of soil especially linked to food refuse (36, 37), 3) changes in fire regimes (38, 39), and, more rarely, 4) the importation of plant propagules from distant sites of collection (40, 41). Identifying such long-lost dynamics between humans and landscapes can inform conservation aimed at restoring site-specific artifacts, features, and the associated resource base past and present, here termed “archaeo-ecosystems” (42, 43). This would greatly facilitate cross-cultural management of public lands (44) in ways that promote Indigenous health, cultural reclamation, and sovereignty (7, 45). The linkages, however, between ecological legacies, archaeo-ecosystem restoration and cross-cultural management have yet to be systematically tested or practically applied.Here, we offer a formal evaluation of this archaeo-ecosystem approach by using paired archaeological and ecological survey data focused on Puebloan occupation of a region known as Bears Ears on the Colorado Plateau in southeastern Utah (Fig. 1). Puebloan populations modified their environment by constructing terraces and check dams, developing blinds and wing traps, importing exogenous species, and setting fires (4, 22, 46), but investments were not uniform across the region. We test the hypothesis that locations with greater investment indicated by larger and more complex archaeological sites should today have higher richness of culturally significant plant species, here termed ethnographic species richness (ESR), as an enduring legacy of past investment. Our study expands previous work on ecological legacies by using field surveys to develop an explanatory model applied to 265 sites across one million acres of semiarid public lands. It documents the occurrence of uncommon and ethnographically significant plant species associated with those sites and infuses traditional ecological knowledge into proposed management actions for conserving these archaeo-ecosystems. Controlling for underlying environmental variation, our results indicate that past human habitation increases the diversity of plant species important for Indigenous subsistence.Open in a separate windowFig. 1.Location of Bears Ears National Monument in southeastern Utah. The predicted ESR at 265 known archaeological sites across the original and reduced monument boundaries and surrounding region are shown.     

Assessing the impacts of livestock production on biodiversity in rangeland ecosystems

Biodiversity in rangelands is decreasing, due to intense utilization for livestock production and conversion of rangeland into cropland; yet the outlook of rangeland biodiversity has not been considered in view of future global demand for food. Here we assess the impact of future livestock production on the global rangelands area and their biodiversity. First we formalized existing knowledge about livestock grazing impacts on biodiversity, expressed in mean species abundance (MSA) of the original rangeland native species assemblages, through metaanalysis of peer-reviewed literature. MSA values, ranging from 1 in natural rangelands to 0.3 in man-made grasslands, were entered in the IMAGE-GLOBIO model. This model was used to assess the impact of change in food demand and livestock production on future rangeland biodiversity. The model revealed remarkable regional variation in impact on rangeland area and MSA between two agricultural production scenarios. The area of used rangelands slightly increases globally between 2000 and 2050 in the baseline scenario and reduces under a scenario of enhanced uptake of resource-efficient production technologies increasing production [high levels of agricultural knowledge, science, and technology (high-AKST)], particularly in Africa. Both scenarios suggest a global decrease in MSA for rangelands until 2050. The contribution of livestock grazing to MSA loss is, however, expected to diminish after 2030, in particular in Africa under the high-AKST scenario. Policies fostering agricultural intensification can reduce the overall pressure on rangeland biodiversity, but additional measures, addressing factors such as climate change and infrastructural development, are necessary to totally halt biodiversity loss.     

Variations in motor conduction velocity produced by acute changes of the metabolic state in diabetic patients

Summary Repeated measurements of motor conduction velocity in 14 primarily untreated diabetics showed a clear improvement in nerve-function during insulin treatment. — Similar results could not he produced by measuring the threshold for vibration sense.

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Veränderungen der motorischen Leitgeschwindigkeit während akuter Stoffwechselschwankungen bei Diabetikern

Zusammenfassung Bei wiederholter Messung der motorischen Leitgeschwindigkeit bei 14 ursprünglich unbehandelten Diabetikern konnte ein Anstieg der Leitgeschwindigkeit während der Behandlung mit Insulin und ein erneuter Abfall nach Unterbrechung der Therapie nachgewiesen werden. — Die Schwelle der Vibrations-empfindung veränderte sich hingegen unter der Insulinbehandlung nicht nachweisbar.

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Variations de la vitesse de conduction des nerfs moteurs provoquées par des modifications aiguës de l'état métabolique chez des diabétiques

Résumé De nombreuses mesures de la vitesse de conduction des nerfs moteurs chez 14 diabétiques n'ayant subi aucune thérapeutique médicamenteuse, ont montré une amélioration évidente du fonctionnement nerveux pendant la durée du traitement à l'insuline, et une détérioration après l'arrêt du traitement. — Des résultats similaires n'ont pas pu être obtenus en mesurant le seuil de la perception vibratoire.

     

Ecological contingency in the effects of climatic warming on forest herb communities

Downscaling from the predictions of general climate models is critical to current strategies for mitigating species loss caused by climate change. A key impediment to this downscaling is that we lack a fully developed understanding of how variation in physical, biological, or land-use characteristics mediates the effects of climate change on ecological communities within regions. We analyzed change in understory herb communities over a 60-y period (1949/1951-2007/2009) in a complex montane landscape (the Siskiyou Mountains, Oregon) where mean temperatures have increased 2 °C since 1948, similar to projections for other terrestrial communities. Our 185 sites included primary and secondary-growth lower montane forests (500-1.200 m above sea level) and primary upper montane to subalpine forests (1,500-2,100 m above sea level). In lower montane forests, regardless of land-use history, we found multiple herb-community changes consistent with an effectively drier climate, including lower mean specific leaf area, lower relative cover by species of northern biogeographic affinity, and greater compositional resemblance to communities in southerly topographic positions. At higher elevations we found qualitatively different and more modest changes, including increases in herbs of northern biogeographic affinity and in forest canopy cover. Our results provide community-level validation of predicted nonlinearities in climate change effects.     

Influence of direct current on the electrical activity of the heart and on its susceptibility to ventricular fibrillation

Summary Isolated perfused guinea pig hearts (Langendorff preparation) were used to study the influence of direct current (DC) on the shape of the electrogram and to determine the thresholds for extrasystoles and for fibrillation. DC impulse durations ranged between 30 ms and 5 s.During DC flow through the heart, marked deformations of the electrogram occur mainly concerning the repolarization phase and increasing with growing current strength. At an intensity of twice the diastolic threshold for stimulation, constant DC induces extrasystoles, which are suggested to result from an enhancement of the intrinsic automatic activity by cathodal polarization.Compared with the diastolic threshold for stimulation, the threshold for fibrillation is higher by a factor of about 15. The curve relating the threshold for fibrillation to the impulse duration shows a marked decline between 30 ms and 60 ms, followed by a slight increase and adjustment to a constant level beyond about 80 ms. In the used setup, the threshold for fibrillation is independent on the reversal of polarity of the electrodes. Long-lasting DC pulses are able to induce fibrillation even if they are switched on in the absolute refractory period of a normal beat.Application of 50-Hz alternating current revealed a higher threshold for stimulation and a three times lower fibrillation threshold compared with the effects of DC in the same heart.

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Zusammenfassung An isolierten Meerschweinchenherzen (Langendroff-Präparation) wurden der Einfluß von Gleichstrom auf das Elektrogramm geprüft und die Schwelle zur Auslösung von Extrasystolen bzw. Kammerflimmern durch Gleichstrom bestimmt. Die Dauer der verwendeten Impulse lag zwischen 30 ms und 5 s.Während Gleichstromeinwirkung kommt es zu beträchtlichen Deformierungen des Elektrogramms besonders in der Repolarisationsphase, die mit der Stromstärke zunehmen. Bei einer Intensität, die etwa der doppelten Reizschwelle entspricht, treten während der Einwirkung von konstantem Gleichstrom Extrasystolen auf, deren Auslösung auf der Stimulation der endogenen Erregungsbildung durch Katelektrotonus beruht.Die Flimmerschwelle für Gleichstrom liegt etwa um einen Faktor 15 höher als die Reiszchwelle. Ihre Beziehung zur Impulsdauer zeigt einen deutlichen Abfall zwischen 30 ms und 60 ms, gefolgt von einem leichten Anstieg und der Einstellung auf ein gleichbleibendes Niveau oberhalb etwa 80 ms. Bei der verwendeten Anordnung ist die Flimmerschwelle unabhängig von der Polungsrichtung der Reizelektroden. Langdauernder Gleichstrom kann Flimmern induzieren, auch wenn er in der absoluten Refraktärperiode eines Normalschlags eingeschaltet wird.Beim Vergleich mit technischem Wechselstrom von 50 Hz liegt am gleichen Herzen die Reizschwelle des Wechselstroms über der für Gleichstrom. Dagegen ist die Flimmerschwelle für Gleichstrom von 1 s Dauer um einen Faktor 3 höher als die Flimmerschwelle für Wechselstrom von 1 s.

     

Simulation of the Kinematic Condition of Radial Shear Rolling and Estimation of Its Influence on a Titanium Billet Microstructure

The finite element method (FEM) computer simulation of the three-high radial shear rolling of Ti-6Al-4V alloy round billets was conducted using QForm software. The simulation was performed for the MISIS-100T rolling mill’s three passes according to the following rolling route: 76 mm (the initial billet diameter) →65 mm→55 mm→48 mm (the final billet diameter). The change in the total velocity values for the points on the radius of the 48 mm diameter billet was estimated while passing the rolls’ draft. The relative increase in the accumulated strain was estimated for the same points. Then, experimental shear rolling was performed. Grain sizes of the α- and β-phases were estimated in the cross section of the final billet at the stationary stage of rolling. The grain size distribution histograms for different phases were plotted. An area was found in the billet’s cross section in which the trend of change in the total velocity of the points changed. This area represented a neutral layer between the slowing peripheral segments of the billet and the accelerating central segments of the billet. Inside this neutral layer, the limits of the cylindrical surface radius value were estimated. Experimental radial shear rolling was performed to compare the experimental rolling results (the billet microstructure investigation) with the computer simulation results. The computer simulation obtained two estimations of the radius limits: 8–16 mm (based on the analysis of the total velocity change) and 12–16 mm (based on the accumulated strain’s relative increment change). The experimental rolling obtained two more estimations of the radius limits: 8.4–19.5 mm and 11.3–19.7 mm—based on the results of the microstructure investigation. It was confirmed that varying the kinematic and deformation parameters of radial shear rolling allows regulation of the thickness of the peripheral fine-grain layer and the diameter of the central coarse-grain layer of the rolled billets.     

Longitudinal assessment of drinking changes during the pandemic: The 2021 COVID-19 follow-up study to the 2019 to 2020 National Alcohol Survey

Background

Surveys of changes in drinking during the COVID-19 pandemic have primarily relied on retrospective self-report. Further, most such surveys have not included detailed measures of alcohol use patterns, such as beverage-specific consumption, nor measures of alcohol use disorder (AUD) symptoms that would allow a comprehensive understanding of changes in alcohol use.

Methods

Data from 1819 completed interviews from the N14C follow-up survey to the 2019 to 2020 National Alcohol Survey (N14) were conducted between January 30 and March 28, 2021. Questions on alcohol use from the Graduated Frequency series, beverage-specific quantity and frequency, and DSM-5 AUD items were asked in both surveys and used to estimate changes from pre-pandemic drinking to drinking during the pandemic. Analyses focus on changes in these measures over time and comparisons between key subgroups defined by gender, race/ethnicity, and age.

Results

Key findings include particularly large increases in drinking and AUD for African Americans and women, reduced drinking and heavy drinking prevalence among men and White respondents, and a concentration of increased drinking and AUD among respondents aged 35 to 49. Increases in alcohol use were found to be driven particularly by increases in drinking frequency and the consumption of spirits.

Conclusions

Results confirm prior findings of overall increases and subgroup-specific changes, and importantly, provide detailed information on the patterns of change across major socio-demographic subgroups. Substantial increases in the prevalence of DSM-5 moderate to severe AUDs are a novel finding that is of particular concern.

     

脑血管对二氧化碳反应中脑血流变化影响因素的临界关闭压研究

目的探讨脑血管对二氧化碳(CO2)反应中脑血流变化的影响因素及其程度。方法同步监测65例健康志愿者正常呼吸、屏气和过度通气时的脑血流、动脉血压、呼出气体CO2分压,并计算临界关闭压(CCP)、脑循环阻力(R)和脑循环灌注压(CPP)。结果屏气时平均动脉压(MABP)和CPP升高,CCP和R降低(P<0.05);过度通气则恰好相反(均P<0.05)。平均血流速度(Vm)的变化受MABP、CCP和R 3种因素的影响,其影响程度在屏气和过度通气中各为29.1%、26.6%、44.3%和42.8%、33.4%、23.8%。结论脑血管对CO2反应的脑血流变化受动脉血压、CCP和R 3种因素的影响,其中动脉血压和CCP对脑灌注压的调控非常重要。     

Effects of exposure to an intensive HIV-prevention programme on behavioural changes among female sex workers in Nairobi,Kenya

While Kenya has had a long-standing national HIV-prevention programme, evidence on the level of exposure to its interventions and related effects on behavioural changes among female sex workers (FSWs) is limited. Using cross-sectional behavioural data collected in 2013 from 1 357 FSWs aged 18 years and above in Nairobi, Kenya, this study explores the relationship between FSW programme exposure levels and behavioural outcomes including condom use, sexually transmitted infection (STI)-treatment, and empowerment measures like disclosure of self-identity and violence reporting. We categorised programme exposure levels as none, moderate and intensive. Multivariate logistic regression was used for analysis. Overall, 35% of the FSWs were not exposed to any HIV prevention programme, whereas about 24% had moderate and 41% had intensive exposure. FSWs having intensive programme exposure had a higher likelihood of using condoms consistently with occasional clients (AOR: 1.57; 95% CI: 1.08–2.31) and seeking treatment for STIs (AOR: 3.37; 95% CI: 1.63–7.02) compared to FSWs with no or moderate exposure. Intensive programme exposure was also associated with higher self-disclosure of sex-work identity (AOR: 1.63; 95% CI: 1.19–2.24), reporting of violence to police (AOR: 2.45; 95% CI: 1.03–5.84), and negotiation of condom use at last sex when the client was under the influence of alcohol (AOR: 1.63; 95% CI: 0.94–2.82). Although HIV prevention programmes in Kenya have been underway for over a decade, programme efforts were largely focused on saturating the coverage (intervention breadth). Strategies should now focus on ensuring improved quality of contacts through intensified programme exposure (intervention depth) to enhance gains in behavioural change among FSWs and preventing the burden of HIV infection among them.     

99mTC_MIBI直肠门脉显影评估普鲁纳洛治疗门脉高压症的疗效

目的采用９９ｍＴＣ＿ＭＩＢＩ直肠门脉显影法测定心肝核素显影比（Ｈ／Ｌ比值）评估普鲁纳洛治疗门脉高压的疗效．方法肝硬变门脉高压患者在普鲁纳洛治疗前后均进行９９ｍＴＣ＿ＭＩＢＩ直肠门脉显影测定，并与对照组结果进行比较分析．结果肝硬变门脉高压者Ｈ／Ｌ显著高于对照组（０．１４±００５，ｎ＝１０，Ｐ＜００１）；肝硬变门脉高压组于普鲁纳洛治疗后Ｈ／Ｌ组较治疗前降低，差异显著（ｎ＝１４，０．５６±０．２２，０．７７±０．２６，Ｐ＝０．０２５）；Ｈ／Ｌ比值＜０．６者曲张静脉破裂出血无复发．结论普鲁纳洛预防肝硬变门脉高压者的曲张静脉破裂出血安全、有效；９９ｍ＿ＴＣ＿Ｍ１Ｂ１直肠门脉显影可作为普鲁纳洛治疗疗效观察的可靠的无创伤性的指标．     

The effect of beta-blockade therapy on the response to exercise training in postmyocardial infarction patients

Cardiac rehabilitation after a myocardial infarction has been shown to improve exercise capacity. Beta blockade has been shown to be effective in treating angina and reducing mortality, but studies are controversial as to whether beta-blockade therapy attenuates the effects of training. We attempted to study the effects of beta blockade (metoprolol) on the response to training in patients enrolled in a cardiac rehabilitation program after an uncomplicated myocardial infarction. We studied 27 patients with a recent uncomplicated myocardial infarction who were subdivided in two groups: Group 1 (13 patients) not taking a beta blocker, and Group 2 (14 patients) taking metoprolol (mean 142 ± 57 mg daily). All patients underwent a maximal cardiopulmonary exercise test before and after a 3-month training program. The training intensity was designed to approximate the ventilatory threshold. Results showed an increase in peak VO₂ in both Group 1 (27%, p<0.01) and Group 2 (33%, p<0.001), and an increase in VO₂ at the ventilatory threshold (39% in Group 1 and 28% in Group 2, p<0.01). The mean changes in exercise capacity were not different between groups. It was concluded that metoprolol did not influence the beneficial effects of a cardiac rehabilitation program in postmyocardial infarction patients.     

The influence of childhood welfare participation on adulthood substance use: evidence from the National Longitudinal Study of Adolescent to Adult Health

Background: The associations between early life-socioeconomic status and health, specifically substance use, are well substantiated. The vulnerabilities associated with adversity in childhood, particularly poverty, can have a cumulative effect on an individual’s risk and resilience throughout the life course. While several studies substantiate the relationship between substance use and welfare participation, less known is the impact of and prevalence of behavioral health problems later in life among young adults who were welfare recipients before age 18. Objective: This article explores whether childhood welfare participation before the age of 18 years influences substance use until young adulthood (24–34 years). Methods: This study used Add Health data with sample sizes ranging from 12,042 to 12,324 respondents, and propensity score matching methods to balance the samples and account for selection bias. Matched data were then used to run a series of regression models. Results: Those who participated in welfare before the age of 18 years had a significant lower probability of remaining substance-free until young adulthood (marijuana-free by 30%, p < 0.001; and other illicit substances-free by 16%, p < 0.05). However, no significant between-group differences were found on any of the alcohol-related variables. Conclusions: Findings highlight long-term behavioral health risks, especially substance use, faced by young adults who participated in welfare before the age of 18 years. Acknowledging the vulnerabilities associated with welfare participation and living in poverty could help increase the effectiveness of program and treatment efforts. The prevention of long-term behavioral health disorders hinges on early diagnosis and intervention.     

Effect of changes in left ventricular anatomy and conduction velocity on the QRS voltage and morphology in left ventricular hypertrophy: a model study

The increased QRS voltage is considered to be a specific electrocardiogram (ECG) sign of left ventricular hypertrophy (LVH), and it is expected that the QRS voltage reflects the increase in left ventricular mass (LVM). However, the increased QRS voltage is only one of QRS patterns observed in patients with LVH. According to the solid angle theory, the resultant QRS voltage is influenced not only by spatial (anatomic) but also by nonspatial (electrophysiologic) determinants. In this study, we used a computer model to evaluate the effect of changes in anatomy and conduction velocity of the left ventricle on QRS complex characteristics.

Material and Methods

The model defines the geometry of cardiac ventricles analytically as parts of ellipsoids and allows to change dimensions of the ventricles, as well as the conduction velocity in the individual layers of myocardium. Three types of anatomic changes were simulated: concentric hypertrophy, eccentric hypertrophy, and dilatation. The conduction velocity was slowed in the inner layer of the left ventricle representing the Purkinje fiber mesh and in the layers representing the working myocardium. The outcomes of the model are presented as the time course of the spatial QRS vector magnitude, the vectorcardiographic QRS loops (VCGs) in horizontal, left sagittal, and frontal planes, as well as derived 12-lead ECGs. The following indicators of the 12-lead ECG were evaluated: the left axis deviation, the intrinsicoid deflection in V6, Cornell voltage, Cornell voltage-duration product, and Sokolow-Lyon index.

Results

The increase in LVM did not affect the QRS voltage proportionally, and the LVM and type of hypertrophy were not the only determinants of the QRS patterns. The conduction velocity slowing resulted in a spectrum of QRS patterns including increased QRS voltage and duration, left axis deviation, prolonged intrinsicoid deflection, VCG patterns of left bundle branch block, as well as pseudo-normal VCG/ECG patterns. The anatomic changes and conduction velocity slowing affected differently Sokolow-Lyon index and Cornell criteria.

Conclusion

We showed that the LVM is not the only determinant of the QRS complex changes in LVH, but it is rather a combination of anatomic and electric remodeling that creates the whole spectrum of the QRS complex changes seen in LVH patients. The slowed conduction velocity in the model heart produced QRS patterns consistent with changes described in LVH, even if the LVM was not changed.     

How much does alcohol contribute to the variability of hepatic fibrosis in chronic hepatitis C?

In order to determine the contribution of alcohol intake to the severity of hepatic fibrosis in patients with chronic hepatitis C, we studied associations between various levels of alcohol intake, other demographic variables and semiquantitative liver histology in 434 cases of chronic hepatitis C. Clinical, demographic and disease-related data were entered into a relational database. Liver histology was scored according to Scheuer. The average daily alcohol intake for the year preceding liver biopsy (recent exposure) and for earlier periods (past exposure) was categorized into five levels of intake. One-third of patients gave a history of alcohol intake that had exceeded 40g/day for at least 5 years. By univariate analysis, age, but not recent or past alcohol intake or other baseline variables, was associated with portal score (r=0.14, P= 0.004), fibrosis score (r= 0.46, P < 0.001), total Scheuer score (r= 0.35, P < 0.001), However, by multivariate analysis, age (P < 0.001), past (but not present) alcohol intake (P < 0.001) and birth in Egypt (P= 0.006) were independently associated with fibrosis score. Age, past alcohol and birth place in Egypt contributed 27% to total variance of the hepatic fibrosis score, while age alone accounted for 23%. Age also independently predicted portal activity (P=0.02) and total Scheuer score (P < 0.001), whereas past alcohol intake correlated with total Scheuer score (P= 0.002) but not with other histological indices. A separate multivariate analysis was performed on a more homogeneous subgroup of 196 patients who acquired hepatitis C by injection drug use. In this subgroup, age (P < 0.05) and past alcohol (P < 0.05) were independently associated with fibrosis score. In both the overall and subgroup analyses, there was a threshold level of past alcohol intake (>80g/day) beyond which the risk of fibrosis increased significantly. It is concluded that toxic levels of alcohol exposure for at least 5 years accentuate hepatic fibrosis in hepatitis C but the influence of alcohol appears to be minor compared with age and other variables and is exerted only at toxic levels of intake.     

The effect of verapamil on ischaemia-induced changes to the sarcolemma

The effect of verapamil on sarcolemmal activities of sarcolemmal fragments isolated from aerobically perfused (control) and ischaemic rat hearts was examined. Adding verapamil to the perfusate of aerobically perfused hearts for 75 min enhanced some of the sarcolemmal activities; Na+-K+ ATPase (31%), K+ stimulated phosphatase (31%) and Na+-Ca2+ exchange rate (46%). Adding verapamil directly to the enzymatic incubation media, or to the cardiac homogenate prior to sarcolemmal isolation did not alter these activities, suggesting that these changes are dependent upon addition of verapamil to the intact system. Addition of verapamil to hearts 15 min prior to a 60 min ischaemic episode maintained a number of sarcolemmal activities close to those obtained after aerobic perfusion. Na+-K+ ATPase activity and Na+-Ca2+ exchange received a relative protection while K+ stimulated phosphatase activity was not protected. 5'-nucleotidase activity was completely protected against ischaemia-induced depression. The mechanism whereby verapamil induces these changes in sarcolemmal enzymatic activities is unclear but its ability to maintain these activities at or near normal levels may contribute to its ability to protect against the deleterious effects of ischaemia.     

DSM-IV to DSM-5: the impact of proposed revisions on diagnosis of alcohol use disorders

Aims To determine the prevalence of past 12‐month DSM‐5 alcohol use disorders (AUDs), to quantify and characterize individuals who remain stably unaffected or affected and those who ‘switch’ diagnostically between DSM‐IV and DSM‐5 classifications. Design Data from the nationally representative wave 2 of the National Epidemiological Survey of Alcohol and Related Conditions (NESARC) collected in 2004–05. Setting General population survey. Participants All surveyed participants (n = 34 653, aged 21 years and older) and 29 993 individuals reporting life‐time alcohol use across both waves of NESARC. Measurements DSM‐IV and DSM‐5 criteria were coded using proposed guidelines. Findings The prevalence of DSM‐5 AUDs was 10.8% with the corresponding prevalence of DSM‐IV abuse/dependence being 9.7%, implying a modest 11.3% increase. Those who switched diagnostically from affected to unaffected (19.6% of DSM‐IV affected) were most likely to have endorsed hazardous use, due particularly to drinking and driving, while those who transitioned from unaffected to affected (3.3% of DSM‐IV unaffected) were primarily DSM‐IV diagnostic orphans reporting larger/longer and quit/cut‐back. Dropping the legal criterion did not affect the prevalence significantly, while the addition of craving also had a relatively modest impact on prevalence. Conclusion The proposed DSM‐5 revisions eliminate successfully individuals diagnosed previously with DSM‐IV alcohol abuse due primarily to hazardous use alone and incorporate diagnostic orphans into the diagnostic realm. Definitions of craving and importantly, hazardous use require considerable attention as it is likely that they will contribute to variations in reports of increased prevalence of alcohol use disorders between DSM‐IV to DSM‐5.