Impact of Rainfall Pattern on Native Arbuscular-Mycorrhizal Activity Influencing Phosphorus Utilization by Direct Seeded Rainfed Upland Rice (Oryza sativa L.)

Efficacy of native arbuscular mycorrhiza to support phosphorus nutrition of rainfed upland rice was assessed under various rainfall patterns. Native arbuscular-mycorrhiza aided phosphorus acquisition by rainfed upland rice (Oryza sativa L.), over the period of 6 years (in alternate year’s between 1999 and 2009) having variable rainfall pattern, under rice mono-cropping and potential arbuscular-mycorrhiza-supportive rice based rotations were compared. Among these, the 2 years rotation of maize (Zea mays L.) relay cropped by horse gram (Dolichos biflorus L.) in the first year and followed by upland rice in the second year was most mycorrhiza-supportive. While phosphorus uptake in rice was positively correlated (r = 0.6301–0.7821) with the extent of mycorrhizal colonization under various crop rotations, the extent of influence of arbuscular-mycorrhizal colonization was greater in less rainfall year of 2009 (R ² = 0.5450) than normal rainfall year of 2007 (R ² = 0.3971). The mycorrhizal advantage to rice under most mycorrhiza supportive crop rotation (maize-horse gram-rice), in terms of mycorrhiza-aided phosphorus acquisition efficiency, on the other hand, was negatively correlated (r = ?0.684 to ?0.799) with the amount of rainfall received over a period under study (6 years), confirming higher mycorrhizal efficacy under moisture stress. The analysis emphasized the potential of exploiting native arbuscular mycorrhizal fungi as climate resilient agricultural technology component in rainfed ecology under the present climate change scenario leading to reducing moisture availability.     

Event related brain potential evidence for preserved attentional set switching in schizophrenia

Pervasive deficits of attention and set switching have been reported in schizophrenia, prompting efforts to identify the information processing mechanisms associated with these deficits. Recent evidence suggests that set switching may be intact in schizophrenia when the task switch requires only a change in the relevance of perceptual dimensions (e.g., attentional set switches) but decision-to-response mappings (intentional set) are maintained across trials in a cued task switching procedure. The goal of the present research was to replicate this finding and to test its direct corollary, which is the unconventional prediction that individuals with schizophrenia will evidence an intact, switch-sensitive P3(b) brain response to cued switches of attentional set. This prediction was tested in a group of 20 individuals with schizophrenia and 20 healthy comparison participants using event-related brain potential methodology and a cued task-switching task. Attentional set switching costs were equivalent between the two groups despite a set maintenance deficit in schizophrenia. Moreover, a posterior-parietal P3(b) component of the ERP was found to be equally sensitive to attentional set switching in schizophrenia and comparison groups, indicating a "healthy" brain response to switches of attentional set in schizophrenia. These results suggest that the dynamic control of attentional set may be preserved in schizophrenia and that previously reported executive deficits may be specific to the control of intentional task set and to deficits of task set maintenance.     

Cerebellum volume and eyeblink conditioning in schizophrenia

Although accumulating evidence suggests that cerebellar abnormalities may be linked to the symptoms and course of schizophrenia, few studies have related structural and functional indices of cerebellar integrity. The present study examined the relationship between the volume of specific subregions of the cerebellum and cerebellar function, as measured by eyeblink conditioning (EBC). Nine individuals with schizophrenia and six healthy comparison participants completed structural magnetic resonance imaging of the brain and a delay EBC procedure. Volumetric measurements were taken for the whole brain, whole cerebellum, cerebellar anterior lobules I-V and posterior lobules VI-VII. The schizophrenia group had smaller cerebellar anterior lobes and exhibited impaired EBC relative to the comparison group. In the comparison group, larger anterior volume correlated with earlier conditioned response onset latencies and increased amplitudes of the unconditioned blink response during paired trials (i.e., when the conditioned and unconditioned stimuli co-occurred). The findings that smaller anterior cerebellar volumes and EBC impairments were associated with schizophrenia are consistent with non-human studies showing that anterior cerebellar abnormalities are associated with deficits in delay EBC. The lack of a significant correlation between indices of EBC and cerebellar volume within the schizophrenia group suggests an aberrant relationship between cerebellar structure and function.     

Uncontrollable voices and their relationship to gating deficits in schizophrenia

BACKGROUND: Prepulse inhibition (PPI) of the startle response refers to the ability of a weak prestimulus to transiently inhibit the response to a closely following strong sensory stimulus. This effect is reduced in a number of disorders known to be associated with impaired gating of sensory, cognitive or motor information. The aim of this study was to investigate PPI deficit in relation to the dimensions of auditory hallucinations in patients with schizophrenia or schizoaffective disorder. METHOD: PPI of the acoustically elicited eye blink startle response was measured electromyographically in 62 patients with schizophrenia (n=55) or schizoaffective disorder (n=7) (26 of 62 with current auditory hallucinations) and 22 healthy participants matched, on average, to age and sex of the patient group. RESULTS: Patients, as a group, showed reduced PPI compared to healthy participants. The presence of auditory hallucinations was associated with a marked PPI deficit if the patients felt that they had no control over their occurrence and that they were unable to dismiss them. Hearing voices with a high degree of negative content was associated with high mean startle amplitude in patients with current auditory hallucinations. CONCLUSIONS: Although auditory hallucinations in patients with schizophrenia are theorised to result from impaired monitoring of inner speech, the inability to consciously ignore them appears to be associated with a gating deficit. Hearing voices with negative content is associated with hyper-startle responding, possibly because such voices are threatening and thus provoke anxiety.     

Abdominal colon and rectal operations in the elderly

Sixty-seven abdominal operations for colon and rectal disorders were performed on 56 patients 80 years of age or older from January 1, 1984 to June 30, 1989. Nine patients required multiple operations. Sixty-two procedures (92 percent) were performed on patients in their ninth decade; two operations were performed on patients 95 years of age or older. Forty-five patients (80 percent) were operated upon for carcinoma. Operations included segmental colectomy (33 patients), low anterior resection (12 patients), total abdominal colectomy (3 patients) and abdominoperineal resection (2 patients). Forty patients were classified as ASA Class III; the majority were monitored in the surgical intensive care unit for a mean of 2.84 days. Thirty patients were monitored with arterial catheters and 21 with central invasive monitoring. Operative mortality was 7 percent (4 patients). Two patients died from diffuse carcinomatosis; one patient had a fatal myocardial infarction. The final death occurred from multisystem organ failure following anastomotic dehiscence. Twenty-seven operations were performed without postoperative complications; 18 operations were followed by a single minor complication. The average hospital stay was 18.96 days. All patients were admitted from home. Thirty-three returned home postoperatively; 16 were discharged to an extended care facility. In conclusion, elderly patients with colon and rectal disorders can be operated upon with acceptable morbidity and mortality. Age alone should not interdict surgical therapy.     

Surgical treatment of low rectovaginal fistulas

Forty women with low rectovaginal fistulas were operated upon over a 9-year period. The etiology of the fistula in the majority was obstetric. Nine women had prior attempts to repair the fistula. All 40 women were managed with endorectal advancement flap with the addition of sphincteroplasty or perineal body reconstruction in 15 patients and rectocele repair in six patients. Postoperative complications included urinary difficulties (two patients) and wound complications (three patients). There were two recurrences. All women treated with sphincteroplasty or perineal body reconstruction were continent. Seven women complained of varying degrees of incontinence postoperatively; none had undergone sphincter or perineal body reconstruction. Endorectal advancement flap is a safe and effective operation for women with rectovaginal fistulas. Concomitant sphincteroplasty or perineal body reconstruction should be performed in women with historical, physical, or manometric evidence of incontinence.     

Steady state visual evoked potential abnormalities in schizophrenia.

OBJECTIVE: The steady state visual evoked potential (SSVEP) can be used to test the frequency response function of neural circuits. Previous studies have shown reduced SSVEPs to alpha and lower frequencies of stimulation in schizophrenia. We investigated SSVEPs in schizophrenia at frequencies spanning the theta (4Hz) to gamma (40Hz) range. METHODS: The SSVEPs to seven different frequencies of stimulation (4, 8, 17, 20, 23, 30 and 40Hz) were obtained from 18 schizophrenia subjects and 33 healthy control subjects. Power at stimulating frequency (signal power) and power at frequencies above and below the stimulating frequency (noise power) were used to quantify the SSVEP responses. RESULTS: Both groups showed an inverse relationship between power and frequency of stimulation. Schizophrenia subjects showed reduced signal power compared to healthy control subjects at higher frequencies (above 17Hz), but not at 4 and 8Hz at occipital region. Noise power was higher in schizophrenia subjects at frequencies between 4 and 20Hz over occipital region and at 4, 17 and 20Hz over frontal region. CONCLUSIONS: SSVEP signal power at beta and gamma frequencies of stimulation were reduced in schizophrenia. Schizophrenia subjects showed higher levels of EEG noise during photic stimulation at beta and lower frequencies. SIGNIFICANCE: Inability to generate or maintain oscillations in neural networks may contribute to deficits in visual processing in schizophrenia.     

Magnetic Resonance Evidence of Perineural Metastasis

Contiguous spread along perineural and endoneural spaces, that is, perineural tumor extension, in cutaneous squamous cell carcinoma is fairly common. Infrequently, these tumors spread and involve intracranial structures. One consequence of th1s complication is meningeal carcinomatosis which is underrecognized. Herein described is a patient with recurrent cutaneous squamous cell carcinoma with perineural invasion along the maxillary nerve that was subsequently shown by magnetic resonance imaging to the trigeminal root The patient Initially presented with a cavernous sinus syndrome but despite aggressive treatment, extensive meningeal carcinomatosis and cauda equina dysfunction developed. Awareness of perineural invasion and proper evaluation are crucial. Penneural spread intracranially worsens the prognosis and limits treatment options to palliation.