Noise reduction of coincidence detector output by the inferior colliculus of the barn owl

A recurring theme in theoretical work is that integration over populations of similarly tuned neurons can reduce neural noise. However, there are relatively few demonstrations of an explicit noise reduction mechanism in a neural network. Here we demonstrate that the brainstem of the barn owl includes a stage of processing apparently devoted to increasing the signal-to-noise ratio in the encoding of the interaural time difference (ITD), one of two primary binaural cues used to compute the position of a sound source in space. In the barn owl, the ITD is processed in a dedicated neural pathway that terminates at the core of the inferior colliculus (ICcc). The actual locus of the computation of the ITD is before ICcc in the nucleus laminaris (NL), and ICcc receives no inputs carrying information that did not originate in NL. Unlike in NL, the rate-ITD functions of ICcc neurons require as little as a single stimulus presentation per ITD to show coherent ITD tuning. ICcc neurons also displayed a greater dynamic range with a maximal difference in ITD response rates approximately double that seen in NL. These results indicate that ICcc neurons perform a computation functionally analogous to averaging across a population of similarly tuned NL neurons

Acute health effects after accidental exposure to styrene from drinking water in Spain.

OBJECTIVES: We studied subjective health symptoms in a population accidentally exposed to high styrene concentrations in drinking tap water. The contamination occurred during the reparation of a water tank. METHODS: Residents of 27 apartments in two buildings using the contaminated water were contacted. A questionnaire on subjective symptoms was administered to 84 out of 93 persons living in the apartments at the time of the accident. Styrene concentration was measured in samples of water collected two days after the accident. The means of exposure associated with appearance of symptoms were examined through case-control analyses. RESULTS: Styrene in water reached concentrations up to 900 microg/L. Symptoms were reported by 46 persons (attack rate 55 %). The most frequent symptoms were irritation of the throat (26%), nose (19%), eyes (18%) and the skin (14%). General gastrointestinal symptoms were observed with 11% reporting abdominal pain and 7% diarrhea. The factors most strongly associated with symptoms were drinking tap water (OR = 7.8, 95% CI 1.3-48), exposure to vapors from the basement (OR = 10.4, 2.3-47) and eating foods prepared with tap water (OR = 8.6, 1.9-40). All residents in the ground floor reported symptoms. CONCLUSIONS: This accidental contamination led to very high styrene concentrations in water and was related to a high prevalence of subjective symptoms of the eyes, respiratory tract and skin. Similar exposures have been described in workers but not in subjects exposed at their residence. Various gastrointestinal symptoms were also observed in this population probably due to a local irritative effect

Lie theory of finite simple groups and the Roth property

AbstractIn noncommutative geometry a ‘Lie algebra’ or bidirectional bicovariant differential calculus on a finite group is provided by a choice of an ad-stable generating subset $\mathcal{C}$ stable under inversion. We study the associated Killing form K. For the universal calculus associated to $\mathcal{C}$ = G \ {e} we show that the magnitude $\mu=\sum_{a,b\in\mathcal{C}}(K^{-1})_{a,b}$ of the Killing form is defined for all finite groups (even when K is not invertible) and that a finite group is Roth, meaning its conjugation representation contains every irreducible, iff μ ≠ 1/(N − 1) where N is the number of conjugacy classes. We show further that the Killing form is invertible in the Roth case, and that the Killing form restricted to the (N − 1)-dimensional subspace of invariant vectors is invertible iff the finite group is an almost-Roth group (meaning its conjugation representation has at most one missing irreducible). It is known [9, 10] that most nonabelian finite simple groups are Roth and that all are almost Roth. At the other extreme from the universal calculus we prove that the 2-cycles conjugacy class in any Sn has invertible Killing form, and the same for the generating conjugacy classes in the case of the dihedral groups D2n with n odd. We verify invertibility of the Killing forms of all real conjugacy classes in all nonabelian finite simple groups to order 75,000, by computer, and we conjecture this to extend to all nonabelian finite simple groups.</jats:p

Anorectal malformations

Anorectal malformations comprise a wide spectrum of diseases, which can affect boys and girls, and involve the distal anus and rectum as well as the urinary and genital tracts. They occur in approximately 1 in 5000 live births. Defects range from the very minor and easily treated with an excellent functional prognosis, to those that are complex, difficult to manage, are often associated with other anomalies, and have a poor functional prognosis. The surgical approach to repairing these defects changed dramatically in 1980 with the introduction of the posterior sagittal approach, which allowed surgeons to view the anatomy of these defects clearly, to repair them under direct vision, and to learn about the complex anatomic arrangement of the junction of rectum and genitourinary tract. Better imaging techniques, and a better knowledge of the anatomy and physiology of the pelvic structures at birth have refined diagnosis and initial management, and the analysis of large series of patients allows better prediction of associated anomalies and functional prognosis. The main concerns for the surgeon in correcting these anomalies are bowel control, urinary control, and sexual function. With early diagnosis, management of associated anomalies and efficient meticulous surgical repair, patients have the best chance for a good functional outcome. Fecal and urinary incontinence can occur even with an excellent anatomic repair, due mainly to associated problems such as a poorly developed sacrum, deficient nerve supply, and spinal cord anomalies. For these patients, an effective bowel management program, including enema and dietary restrictions has been devised to improve their quality of life

Tissue-specific dysregulation of mitochondrial respiratory capacity and coupling control in colon-26 tumor-induced cachexia

In addition to skeletal muscle dysfunction, cancer cachexia is a systemic disease involving remodeling of non-muscle organs such as adipose and liver. Impairment of mitochondrial function is associated with multiple chronic diseases. The tissue-specific control of mitochondrial function in cancer cachexia is not well-defined. This study determined mitochondrial respiratory capacity and coupling control of skeletal muscle, white adipose tissue (WAT), and liver in colon-26 (C26) tumor-induced cachexia. Tissues were collected from PBS-injected weight-stable mice, C26 weight-stable mice, and C26 mice with moderate (10% weight loss) and severe cachexia (20% weight loss). The respiratory control ratio (RCR, an index of OXPHOS coupling efficiency) was low in WAT during the induction of cachexia, due to high non-phosphorylating LEAK respiration. Liver RCR was low in C26 weight-stable and moderately cachexic mice due to reduced OXPHOS. Liver RCR was further reduced with severe cachexia, where Ant2 but not Ucp2 expression was increased. Ant2 was inversely correlated with RCR in the liver (r=-0.547, p<0.01). Liver cardiolipin increased in moderate and severe cachexia, suggesting this early event may also contribute to mitochondrial uncoupling. Impaired skeletal muscle mitochondrial respiration occurred predominantly in severe cachexia, at complex I. These findings suggest that mitochondrial function is subject to tissue-specific control during cancer cachexia, whereby remodeling in WAT and liver arise early and may contribute to altered energy balance, followed by impaired skeletal muscle respiration. We highlight an under-recognized role of liver and WAT mitochondrial function in cancer cachexia, and suggest mitochondrial function of multiple tissues to be therapeutic targets

A prospective, multi centre, randomized clinical study to compare the efficacy and safety of Ertapenem 3 days versus Ampicillin - Sulbactam 3 days in the treatment of localized community acquired intra-abdominal infection. (T.E.A. Study: Three days Ertapenem vs three days Ampicillin-sulbactam)

<p>Abstract</p> <p>Background</p> <p>The recommendations outlined in the latest guidelines published by the Surgical Infection Society (SIS) and the Infectious Disease Society of America (IDSA) regarding the proper duration of antibiotic therapy in patients with intra-abdominal infections are limited and non-specific. This ambiguity is due mainly to the lack of clinical trials on the topic of optimal duration of therapy. It is well known that the overuse of antibiotics has several important consequences such as increased treatment costs, reduced clinical efficacy, and above all, the increased emergence of antibiotic-resistant pathogens. Ampicillin-Sulbactam is a commonly used "first line" antibiotic for intra-abdominal infections. Ertapenem and Ampicillin-sulbactam are recommended as primary treatment agents for localized peritonitis by both the SIS and IDSA guidelines.</p> <p>Methods/Design</p> <p>This study is a prospective multi-center randomized investigation. The study will be performed in the Departments of General, Emergency, and Transplant Surgery of Sant'Orsola-Malpighi University Hospital in Bologna, Italy, in the General Surgery Department of the Ospedali Riuniti of Bergamo, Italy, and in the Trauma and Emergency Surgery Department of Maggiore Hospital in Bologna, Italy, and will be conducted by all surgeons willing to participate in the study. The inclusion period of the study will take approximately two years before the planned number of 142 enrolled patients is reached.</p> <p>Discussion</p> <p>Ertapenem and Ampicillin-sulbactam are recommended both as primary treatment agents for localized peritonitis by both the SIS and IDSA guidelines. As one of the discussed topic is the optimal duration of the antibiotic therapy and this ambiguity is due mainly to the lack of clinical trials on the topic, the present study aims for obtain precise data.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00630513">NCT00630513</a></p

TGF-beta(2)- and H2O2-Induced Biological Changes in Optic Nerve Head Astrocytes Are Reduced by the Antioxidant Alpha-Lipoic Acid

Background/Aims: The goal of the present study was to determine whether transforming growth factor-beta(2) (TGF-beta(2))- and oxidative stress-induced cellular changes in cultured human optic nerve head (ONH) astrocytes could be reduced by pretreatment with the antioxidant alpha-lipoic acid (LA). Methods: Cultured ONH astrocytes were treated with 1.0 ng/ml TGF-beta(2) for 24 h or 200 mu M hydrogen peroxide (H2O2) for 1 h. Lipid peroxidation was measured by a decrease in cis-pari-naric acid fluorescence. Additionally, cells were pretreated with different concentrations of LA before TGF-beta 2 or H2O2 exposure. Expressions of the heat shock protein (Hsp) alpha B-crystallin and Hsp27, the extracellular matrix (ECM) component fibronectin and the ECM-modulating protein connective tissue growth factor (CTGF) were examined with immunohistochemistry and real-time PCR analysis. Results: Both TGF-beta(2) and H2O2 increased lipid peroxidation. Treatment of astrocytes with TGF-beta(2) and H2O2 upregulated the expression of alpha B-crystallin, Hsp27, fibronectin and CTGF. Pretreatment with different concentrations of LA reduced the TGF-beta(2)- and H2O2-stimulated gene expressions. Conclusion: We showed that TGF-beta(2)- and H2O2-stimulated gene expressions could be prevented by pretreatment with the antioxidant LA in cultured human ONH astrocytes. Therefore, it is tempting to speculate that the use of antioxidants could have protective effects in glaucomatous optic neuropathy. Copyright (C) 2012 S. Karger AG, Base

Poverty, social exclusion and dental caries of 12-year-old children: a cross-sectional study in Lima, Peru

Background: Socioeconomic differences in oral health have been reported in many countries. Poverty and social exclusion are two commonly used indicators of socioeconomic position in Latin America. The aim of this study was to explore the associations of poverty and social exclusion with dental caries experience in 12-year-old children. Methods: Ninety families, with a child aged 12 years, were selected from 11 underserved communities in Lima (Peru), using a two-stage cluster sampling. Head of households were interviewed with regard to indicators of poverty and social exclusion and their children were clinically examined for dental caries. The associations of poverty and social exclusion with dental caries prevalence were tested in binary logistic regression models. Results: Among children in the sample, 84.5% lived in poor households and 30.0% in socially excluded families. Out of all the children, 83.3% had dental caries. Poverty and social exclusion were significantly associated with dental caries in the unadjusted models (p = 0.013 and 0.047 respectively). In the adjusted model, poverty remained significantly related to dental caries (p = 0.008), but the association between social exclusion and dental caries was no longer significant (p = 0.077). Children living in poor households were 2.25 times more likely to have dental caries (95% confidence interval: 1.24; 4.09), compared to those living in non-poor households. Conclusion: There was support for an association between poverty and dental caries, but not for an association between social exclusion and dental caries in these children. Some potential explanations for these findings are discussed