Seasonal pattern of Fasciola hepatica antibodies in dairy herds in Northern Germany

Fasciolosis, caused by the liver fluke Fasciola hepatica, is one of the most important parasitoses in cattle farming worldwide. In dairy cows, the trematode leads to economic losses due to decreased milk yield, a negative impact on reproduction parameters, and liver condemnations. In the present study, the seasonal patterns of F. hepatica antibodies in bulk-tank milk from dairy herds located in East Frisia, a region of the federal state Lower Saxony in the north of Germany, were investigated. This region was chosen since it is known as a high risk area for fluke infections due to its coastal location at the North Sea with the consequence of rather moist pastures. Between 669 and 868 bulk-tank milk samples were collected in January, September and November 2008 and 2010, respectively, and analysed for antibodies against F. hepatica with an in-house ELISA based on excretory-secretory antigens of the liver fluke. The overall East Frisian prevalence was 49.1%, 57.1% and 53.9% in January, September and November 2008 and 45.1%, 49.5% and 48.4% in 2010. From a number of 606 farms, which were sampled in all six investigated months, 34.5% of the farms continued to remain positive, whereas 30.9% continued to remain negative. A percentage of 69.1% (419 farms) were positive on at least one sampling occasion during the study period. The distributions of optical density ratio (ODR) values were skewed to the left but showed a second, lower peak in a high ODR range. Statistical analysis revealed a significant difference concerning the prevalence increase from January to September 2008. Furthermore, the prevalence decrease from September as well as November 2008 to these months in 2010 was significantly different, what might result from a more frequent use of anthelminthics or different climatic conditions.     

Enhanced production of low energy electrons by alpha particle impact

Radiation damage to living tissue stems not only from primary ionizing particles but to a substantial fraction from the dissociative attachment of secondary electrons with energies below the ionization threshold. We show that the emission yield of those low energy electrons increases dramatically in ion-atom collisions depending on whether or not the target atoms are isolated or embedded in an environment. Only when the atom that has been ionized and excited by the primary particle impact is in immediate proximity of another atom is a fragmentation route known as interatomic Coulombic decay (ICD) enabled. This leads to the emission of a low energy electron. Over the past decade ICD was explored in several experiments following photoionization. Most recent results show its observation even in water clusters. Here we show the quantitative role of ICD for the production of low energy electrons by ion impact, thus approaching a scenario closer to that of radiation damage by alpha particles: We choose ion energies on the maximum of the Bragg peak where energy is most efficiently deposited in tissue. We compare the electron production after colliding He(+) ions on isolated Ne atoms and on Ne dimers (Ne(2)). In the latter case the Ne atom impacted is surrounded by a most simple environment already opening ICD as a deexcitation channel. As a consequence, we find a dramatically enhanced low energy electron yield. The results suggest that ICD may have a significant influence on cell survival after exposure to ionizing radiation.     

The optimality of sensory processing during the speed-accuracy tradeoff

When people make decisions quickly, accuracy suffers. Traditionally, speed-accuracy tradeoffs (SATs) have been almost exclusively ascribed to changes in the amount of sensory evidence required to support a response ("response caution") and the neural correlates associated with the later stages of decision making (e.g., motor response generation and execution). Here, we investigated whether performance decrements under speed pressure also reflect suboptimal information processing in early sensory areas such as primary visual cortex (V1). Human subjects performed an orientation discrimination task while emphasizing either response speed or accuracy. A model of choice behavior revealed that the rate of sensory evidence accumulation was selectively modulated when subjects emphasized accuracy, but not speed, suggesting that changes in sensory processing also influence the SAT. We then used fMRI and a forward encoding model to derive orientation-selective tuning functions based on activation patterns in V1. When accuracy was emphasized, the extent to which orientation-selective tuning profiles exhibited a theoretically optimal gain pattern predicted both response accuracy and the rate of sensory evidence accumulation. However, these relationships were not observed when subjects emphasized speed. Collectively, our findings suggest that, in addition to lowered response thresholds, the performance decrements observed during speeded decision making may result from a failure to optimally process sensory signals.     

Practices of receptive and insertive anal sex among transgender women in relation to partner types,sociocultural factors,and background variables

It is urgent to develop efficacious HIV prevention programs to curb the reported extremely high HIV prevalence and incidence among transgender women (male-to-female transgender persons) who reside in large cities in the USA. This study aimed to describe unprotected receptive anal sex (URAS) and unprotected insertive anal sex (UIAS) among high-risk transgender women in relation to partner types, psychosocial factors, and background variables. Based on purposive sampling from the targeted communities and AIDS service organizations in San Francisco and Oakland, a total of 573 transgender women who had a history of sex work were recruited and individually interviewed using a structured survey questionnaire. Significant correlates with URAS with primary, casual, and commercial sex partners were found (e.g., needs for social support, frequency of social support received, exposure to transphobia, self-esteem, economic pressure, norms toward practicing healthy behaviors, and self-efficacy toward practicing safe sex). Multiple logistic regression analyses revealed that transgender women who had engaged in URAS with commercial partners were more likely to have higher levels of transphobia or lower levels of the norms or self-efficacy to practice safe sex. Among the participants who did not have vaginoplasty (preoperative transgender women), 16.4% had engaged in insertive anal sex (IAS) with commercial partners in the past 30 days. The participants who were HIV positive and had engaged in IAS were more likely to be African-American or Caucasians, coinfected with sexually transmitted infections, or identified themselves as homosexual. Practices of IAS among transgender women have not been thoroughly investigated in relation to sexual and gender identity. UIAS with homosexual and bisexual men in addition to URAS may be a cause for high HIV incidence among transgender women. An HIV prevention intervention study must be developed and evaluated, which aims to reduce HIV-positive and -negative transgender women's URAS and UIAS.     

A 12 month clinical study of bond failures of recycled versus new stainless steel orthodontic brackets

The purpose of this prospective longitudinal randomized study was to compare the clinical performance of recycled brackets with that of new stainless steel brackets (Orthos). Twenty patients treated with fixed appliances were included in the investigation. Using a 'split-mouth' design, the dentition of each patient was divided into four quadrants. In 11 randomly selected patients, the maxillary left and mandibular right quadrants were bonded with recycled brackets, and the remaining quadrants with new stainless steel brackets. In the other nine patients the quadrants were inverted. Three hundred and ten stainless steel brackets were examined: 156 were recycled and the remaining 154 were new. All the brackets were bonded with a self-cured resin-modified glass ionomer (GC Fuji Ortho). The number, cause, and date of bracket failures were recorded over 12 months. Statistical analysis was performed by means of a paired t-test, Kaplan-Meier survival estimates, and the log-rank test. No statistically significant differences were found between: (a) the total bond failure rate of recycled and new stainless steel brackets; (b) the upper and lower arches; (c) the anterior and posterior segments. These findings demonstrate that recycling metallic orthodontic brackets can be of benefit to the profession, both economically and ecologically, as long as the orthodontist is aware of the various aspects of the recycling methods, and that patients are informed about the type of bracket that will be used for their treatment.     

Clinical factors and self‐perceived oral health

Self‐perceived oral health is affected not only by awareness of the clinical status but also by comparisons with people of a similar age. This study explored the relative contributions of clinical variables assessing caries, periodontal status, and prosthetic status to self‐perceived oral health within two age groups. Data of 891 adults (35–44 yr of age) and 760 older people (65–74 yr of age) from the Fourth German Oral Health Study (DMS IV, 2005) were evaluated. Self‐perceived oral health was obtained from questionnaires. Numbers of decayed, filled, and unreplaced teeth, mean attachment loss, bleeding on probing (BOP), the presence of a fixed denture, and the presence of a removable denture were assessed. Multinomial logistic regression models were developed for both age groups, separately, using stepwise methods. For adults, unreplaced teeth, filled teeth, decayed teeth, the presence of a removable denture, and mean attachment loss were added to the final model. For older people, the presence of a removable denture, unreplaced teeth, decayed teeth, mean attachment loss, filled teeth, and BOP were included in the final model. Awareness of the relative contributions of clinical variables to self‐perceived oral health is important for obtaining a clearer understanding of patients' subjective and objective self‐perceptions of oral health.