Characterization of extracellular spike waveforms recorded in wallaby primary visual cortex.

Extracellular recordings were made from 642 units in the primary visual cortex (V1) of a highly visual marsupial, the Tammar wallaby. The receptive field (RF) characteristics of the cells were objectively estimated using the non-linear input model (NIM), and these were correlated with spike shapes. We found that wallaby cortical units had 68% regular spiking (RS), 12% fast spiking (FS), 4% triphasic spiking (TS), 5% compound spiking (CS) and 11% positive spiking (PS). RS waveforms are most often associated with recordings from pyramidal or spiny stellate cell bodies, suggesting that recordings from these cell types dominate in the wallaby cortex. In wallaby, 70-80% of FS and RS cells had orientation selective RFs and had evenly distributed linear and nonlinear RFs. We found that 47% of wallaby PS units were non-orientation selective and they were dominated by linear RFs. Previous studies suggest that the PS units represent recordings from the axon terminals of non-orientation selective cells originating in the lateral geniculate nucleus (LGN). If this is also true in wallaby, as strongly suggested by their low response latencies and bursty spiking properties, the results suggest that significantly more neurons in wallaby LGN are already orientation selective. In wallaby, less than 10% of recorded spikes had triphasic (TS) or sluggish compound spiking (CS) waveforms. These units had a mixture of orientation selective and non-oriented properties, and their cellular origins remain difficult to classify.

Socioeconomic Status and Domostic Violence Interact in Perdict of Quality of Life in Married Women: A Population-Based Study in Westeren Iran.

Objective: Women's quality of life is essential both for women's and their family's health. The aim of this study was to examine the quality of life status and interaction of subjective socioeconomic status and violence, on quality of life of married women in west of Iran. Materials and methods: This was a cross-sectional study that recruited 1533 married women using multi-stages sampling method. Multiple linear regression was employed for estimating adjusted association and 95% confidence intervals. Results: The mean (SD) age of the participants was 33.67(11). The majority of participants (92%) experienced some degree of domestic violence. Less than half of women (46.70%) perceived medium socioeconomic status. Mean (SD) score of quality of life was 3.57 (0.94). There was a significant statistical interaction between socioeconomic status and domestic violence on quality of life. Conclusion: These findings suggest that considering the interaction of subjective socioeconomic status with domestic violence in prevention program, especially in poor categories of family, appears to be one of the important ways in improving married-females' quality of life.

Microplastic abundance, distribution, and characterization in freshwater sediments in Iran: a case study in Kermanshah city.

This paper focuses on abundance, distribution, and characteristics of microplastics (MPs) in freshwater sediments of Sarab Niloofar Lake, Kermanshah, Iran. After selecting an appropriate method for extraction of MPs, the characterization such as polymer types, surface morphology, and trace elements has been determined using Fourier transform infrared spectroscopy, scanning electron microscopic, and energy-dispersive X-ray spectroscopic analysis, respectively. The results highlighted that all sampling locations were contaminated by MP abundance ranged from 1733.33 to 4400 items kg-1 d.w with an average of 2483.59 ± 805.30 items kg-1 d.w. MPs with a size range of 0.025 to 1 mm (25-1000 µm) were the most frequently detected MPs in size (62%). Furthermore, the MPs found in this area mainly contain fiber (61%), fragment (19%), film (9%), foam (6%), and pallet (5%). The main color for detected MPs in sampling stations was black (51%) and followed by white/transparent (27%), red (11%), blue (7%), and yellow (4%). The results of polymer identification revealed that the polyethylene, polystyrene, polyurethane, and polypropylene were the principal polymers. This research work emphasized that various types of MPs have been distributed in freshwater sediments of Sarab Niloofar Lake, which is a first useful data for MPs in one the most important Kermanshah's tourist area.

Trauma and its consequences in Iran: cross-cultural adaption and validation of the Global Psychotrauma Screen in a representative sample.

BACKGROUND: Potentially traumatic events may lead to the development of a wide range of adverse psychological responses, including symptoms of anxiety, depression, and (complex) posttraumatic stress disorder (PTSD). Despite the high prevalence of potentially traumatic events in Iran, there is no population data nor evidence-based instrument to screen for cross-diagnostic psychological responses to trauma. The Global Psychotrauma Screen (GPS) is a transdiagnostic self-report instrument for the detection of trauma-related symptoms, as well as risk and protective factors related to the impact of potentially traumatic events. OBJECTIVE: The present study seeks to 1) translate and cross-culturally adapt the GPS in the Persian (Farsi) language and 2) examine the psychometric properties of the Persian GPS. METHOD: The translation and adaptation were performed using the Sousa and Rojjanasrirat (2011) method. A pilot study (n = 30) was carried out to test the content validity and test-retest reliability of the GPS. Next, in a representative sample (n = 800) of residents of Kermanshah City, the GPS, the General Health Questionnaire (GHQ) and the PTSD Checklist for DSM-5 (PCL-5) were administered. Construct validity of the Persian GPS was assessed using exploratory and confirmatory factor analysis. Additionally, we evaluated the convergent validity and internal consistency of the GPS. RESULTS: Exploratory and confirmatory factor analyses indicated a three-factor model as the best solution with factors representing 1) Negative Affect, 2) Core PTSD symptoms and 3) Dissociative symptoms. The GPS total symptom score had high internal consistency and high convergent validity with related measures. A GPS total symptom cut-off score of nine was optimal for indicating a probable PTSD diagnosis based on the PCL-5. About half (52%) of the current sample met criteria for probable PTSD. CONCLUSIONS: The current findings suggest that the GPS can be effectively adapted for use in a non-Western society and, specifically, that the Persian GPS represents a useful, reliable and valid tool for screening of trauma-related symptoms in Iran.

Optimizing parameters of the Pulsed Dye Laser (PDL, 585-nm) for hemangioma treatment using diffuse reflectance spectroscopy.

INTRODUCTION: The lack of objectivity options for a specific individualized therapy might cause challenges in laser treatment. In other words, we need optimally determined laser parameters for less side effects. Generally, laser treatment procedures seem to be subjective. Then, the final evaluation of the patient needs for optimized better response with less laser sections and less side effects. Therefore, employing a reliable objective technique seems to be essential for better response with less laser treatment sessions and also less side effects. METHOD: In this research, UV-visible diffused reflection spectra from normal skin and a lesion were taken. We obtained the differences in absorption intensity at 575 nm, the wavelength corresponds to the absorption peak of blood oxyhemoglobin for normal skin and hemangioma. To calibrate the measurements, after using pulsed dye laser (PDL at 585 nm), the PDL treatment response of the patients were graded as "good (>50%), moderate(25%-50%), and poor (0%-25%)," by a specialist. Finally, patients were categorized based on the energy of the laser for the best treatment response to propose the recommended laser parameters. RESULTS: Based on the differences in the absorption peak hemangioma compare with normal skin, the energy density of PDL for a good treatment response of hemangioma was obtained at peak wavelength 575 nm. CONCLUSION: The analysis of optical reflection spectroscopy can assess the correlation of absorption peak differences of vascular lesions and normal skin. According to this data, it seems to be effective in optimizing lasers parameters for the hemangioma treatment.

Exploring the epidemiology of suicide attempts: Risk modeling in Kermanshah-Iran.

Background: Suicide attempt is a serious global public health issue. The patterns of suicide may vary depending on the individual characteristics, methods, causes, and the geographical area-also socio-cultural context that determine it. This study identifies the spatial patterns of suicide attempts in Kermanshah province, Iran. Method: The sample size of this cross-sectional study is 18,331 people (7234 males and 11097 females) who attempted suicide in Kermanshah province between 2006 and 2014. Data was collected from the records of patients referred to the emergency department of hospitals in Kermanshah and analyzed using tests of Mean Center, Standard Distance, and Average Nearest Neighbor. Results: The results of the mean center and standard distance tests show that drug overdose, poisoning with toxins and pesticides, and chemicals mostly were used in the central areas of Kermanshah province. The mean center of suicide attempts by self-immolation, hanging and firearms was in the western parts of the province, while the suicide attempts with narcotic drug were concentrated in the eastern regions of the province. Out of the 18,331 cases, 74% attempted suicide with drug overdose, 13% with toxins and pesticides, 0.59% with chemicals, 4% with fire, 1% by self-immolation, 1% by hanging, 0.16% with firearms and 0.7% with cold weapons. The spatial pattern of all suicide attempts in Kermanshah was clustered (Z-score < -2.58). Conclusion: The results of this study show that the methods of suicide attempt vary with geographical areas in the province. Therefore, it is suggested that planning tailored to the geographical location can reduce suicide attempts in Kermanshah.

The role of risk perception, risk communication, and demographic factors in COVID-19 preventive behaviors: an online survey in Iran.

OBJECTIVES: This study investigated preventive behaviors toward coronavirus disease 2019 (COVID-19) and related factors in a Kurdish Iranian sample. METHODS: This online survey was conducted among the population aged 18 and above in Kermanshah Province, in western Iran, in April 2020. Samples were invited and recruited through social media. Data were collected using a questionnaire consisting of 4 sections (questions on demographic variables, risk perception, risk communication, and COVID-19 preventive behaviors) and analyzed using Stata ver. 8. RESULTS: The Pearson correlation test showed that risk communication was significantly correlated with COVID-19 preventive behaviors (r=0.320, p<0.01). In the final model, where the explanatory power increased with the entry of the risk communication variable, the variables explained a total of 14% of variance in COVID-19 preventive behaviors. Sex (ß=-0.482), risk perception (ß=0.047), and risk communication (ß=0.662) were significant determinants. CONCLUSION: Risk communication and risk perception related to COVID-19, as well as being a woman, were determinants of COVID-19 preventive behaviors.

Orientation pinwheels in primary visual cortex of a highly visual marsupial.

Primary visual cortices in many mammalian species exhibit modular and periodic orientation preference maps arranged in pinwheel-like layouts. The role of inherited traits as opposed to environmental influences in determining this organization remains unclear. Here, we characterize the cortical organization of an Australian marsupial, revealing pinwheel organization resembling that of eutherian carnivores and primates but distinctly different from the simpler salt-and-pepper arrangement of eutherian rodents and rabbits. The divergence of marsupials from eutherians 160 million years ago and the later emergence of rodents and rabbits suggest that the salt-and-pepper structure is not the primitive ancestral form. Rather, the genetic code that enables complex pinwheel formation is likely widespread, perhaps extending back to the common therian ancestors of modern mammals.

Investigating Global Spatial Patterns of Diarrhea-Related Mortality in Children Under Five.

Objective: Investigating the trends of child diarrhea-related mortality (DRM) is crucial to tracking and monitoring the progress of its prevention and control efforts worldwide. This study explores the spatial patterns of diarrhea-related mortality in children under five for monitoring and designing effective intervention programs. Methods: The data used in this study was obtained from the World Health Organization (WHO) public dataset that contained data from 195 countries from the year 2000 to 2017. This dataset contained 13,541,989 DRM cases. The worldwide spatial pattern of DRM was analyzed at the country level utilizing geographic information system (GIS) software. Moran's I, Getis-Ord Gi, Mean center, and Standard Deviational Ellipse (SDE) techniques were used to conduct the spatial analysis. Results: The spatial pattern of DRM was clustered all across the world during the study period from 2000 to 2017. The results revealed that Asian and African countries had the highest incidence of DRM worldwide. The findings from the spatial modeling also revealed that the focal point of death from diarrhea was mainly in Asian countries until 2010, and this focus shifted to Africa in 2011. Conclusion: DRM is common among children who live in Asia and Africa. These concentrations may also be due to differences in knowledge, attitude, and practices regarding diarrhea. Through GIS analysis, the study was able to map the distribution of DRM in temporal and spatial dimensions and identify the hotspots of DRM across the globe.

How Stimulus Statistics Affect the Receptive Fields of Cells in Primary Visual Cortex.

We studied the changes that neuronal receptive field (RF) models undergo when the statistics of the stimulus are changed from those of white Gaussian noise (WGN) to those of natural scenes (NSs), by fitting the models to multielectrode data recorded from primary visual cortex (V1) of female cats. This allowed the estimation of both a cascade of linear filters on the stimulus, as well as the static nonlinearities that map the output of the filters to the neuronal spike rates. We found that cells respond differently to these two classes of stimuli, with mostly higher spike rates and shorter response latencies to NSs than to WGN. The most striking finding was that NSs resulted in RFs that had additional uncovered filters compared with WGN. This finding was not an artifact of the higher spike rates observed for NSs relative to WGN, but rather was related to a change in coding. Our results reveal a greater extent of nonlinear processing in V1 neurons when stimulated using NSs compared with WGN. Our findings indicate the existence of nonlinear mechanisms that endow V1 neurons with context-dependent transmission of visual information.SIGNIFICANCE STATEMENT This study addresses a fundamental question about the concept of the receptive field (RF): does the encoding of information depend on the context or statistical regularities of the stimulus type? We applied state-of-the-art RF modeling techniques to data collected from multielectrode recordings from cat visual cortex in response to two statistically distinct stimulus types: white Gaussian noise and natural scenes. We find significant differences between the RFs that emerge from our data-driven modeling. Natural scenes result in far more complex RFs that combine multiple features in the visual input. Our findings reveal that different regimes or modes of operation are at work in visual cortical processing depending on the information present in the visual input. The complexity of V1 neural coding appears to be dependent on the complexity of the stimulus. We believe this new finding will have interesting implications for our understanding of the efficient transmission of information in sensory systems, which is an integral assumption of many computational theories (e.g., efficient and predictive coding of sensory processing in the brain).

Social Determinants of Adherence to COVID-19 Preventive Guidelines in Iran: A Qualitative Study.

INTRODUCTION: Adherence to COVID-19 preventative guidelines may be influenced by a variety of factors at the individual, societal, and institutional levels. The current study sought to investigate the social factors of adherence to those preventive measures from the perspective of health professionals. METHODS: In October 2020, we performed qualitative research in Tehran, Iran, using the directed content analysis method. For the preparation of our interview guide and data analysis, we employed the WHO conceptual framework of socioeconomic determinants of health. Semi-structured interviews were conducted with 15 health professionals and policymakers who were chosen using a purposive sampling approach. MAXQDA-18 software was used to analyze the data. The Goba and Lincoln criteria were used to assess the quality of the results. RESULTS: There are 23 subcategories and 9 categories, which include socio-economic and political context (unstable macroeconomic environment, poor management of the pandemic, media and knowledge transfer), cultural and social values (fatalism, cultural norms, value conflicts, social customs), socio-economic positions (livelihood conditions), social capital (social cohesion, low trust), living conditions (housing conditions), occupational conditions (precarious employment), individual characteristics (demographic characteristics, personality traits, COVID-19 knowledge, and attitude), psycho-social factors (normalization of the disease, social pressure, and stigma), and health system leadership (health system problems, not taking evidence-based decisions, non-comprehensive preventive guidelines, non-operational guidelines, inadequate executive committee) were obtained. CONCLUSION: To limit the new COVID-19 transmission, people must be encouraged to follow COVID-19 prevention instructions. Improving adherence to COVID-19 preventive guidelines necessitates dealing with the complexities of responding to social determinants of those guidelines. Increasing public health literacy and knowledge of COVID-19, informing people about the consequences of social interactions and cultural customs in the spread of COVID-19, strengthening regulatory lockdown laws, improving guarantees for adhering to preventive guidelines, providing easy access to preventive supplies, and strengthening financial support for households with precarious employment are all important.

Investigating geographical accessibility and site suitability of medical laboratories in Kermanshah-Iran.

Introduction: One of the major challenges in developing countries is the inappropriate spatial distribution of medical laboratory centers (MLCs) which can lead to injustice in access to health services. This study aimed to investigate the accessibility to and site suitability of MLCs in Kermanshah Metropolis by GIS. Materials and methods: In this cross-sectional study, data were collected from the Iran Statistical Center and Deputy of Treatment of Kermanshah University of Medical Sciences. We used Arc/GIS 10.6 software, AHP technique, and network analysis tools to determine the access status of Kermanshah citizens to MLCs in 2019 and site selection for MLCs. The layers used in this study included population density, city development trends, compatible and incompatible land uses, pathways, land slope, river area, and access radius. Results: About 70% of households had inappropriate access to all MLCs in walking scenario. This ratio was 31.26% for 5 min, 9.58% for 10 min, and 6.09% for 15 min driving. Comparisons between public and private MLCs showed that in walking scenario, 88% of households had improper access to public and 80% to private MLCs. Based on 5 and 10 min of driving, 57 and 19% of households had inappropriate access to public MLCs, and 45 and 17% to private MLCs, respectively. Also, with 15 min of driving, 8% of households had improper access to public and 18% to private MLCs. Findings showed that scores provided for population density criteria were (0.298), distance from existing laboratories (0.213), proximity to pathways (0.175), consistent land use (0.129), city development trend (0.087), distance from riverfront (0.053), distance from incompatible land uses (0.015), and land slope (0.03). The final model was obtained by overlaying the layers. The model showed a 9-degree range from very bad to very good in Kermanshah city for the construction of laboratory centers (CR<0.01). Conclusion: The site selection model showed that the location of the proposed centers can be in the north and outskirts of the city to facilitate citizens' access to the MLCs. These results emphasize the justice in the spatial distribution of MLCs for the benefit of deprived populations as a global value.

Social determinants of adherence to COVID-19 preventive guidelines: a comprehensive review.

Adherence to coronavirus disease 2019 (COVID-19) preventive guidelines (ACPG) is an important strategy to control the COVID-19 pandemic effectively. The present study aimed to identify and summarize the social determinants of ACPG among the general population. A comprehensive review was performed from December 2019 to February 2021 through searching electronic databases. Two independent reviewers assessed and selected relevant studies. Next, the characteristics and main findings of the included studies were summarized. Finally, the World Health Organization's conceptual framework of social determinants of health was used to synthesize the identified social determinants of ACPG. Forty-one of 453 retrieved articles met the inclusion criteria. The study results showed different patterns of ACPG among various communities. Furthermore, 84 social determinants were identified and categorized into structural and intermediary determinants. ACPG is a set of complex behaviors associated with different individual sociodemographic and behavioral characteristics; living and working conditions; COVID-19 knowledge, attitudes, and risk perceptions; exposure to sources and information level; leisure activities; social support; trust; social norms; psychosocial well-being; socio-economic position; and the socio-economic and political context. Interventions to promote ACPG among the general population should consider the identified social determinants of ACPG.

Survey on the indexes of health equity in the physical environment and infrastructures of Kermanshah province, Iran.

BACKGROUND: Health equity is directly associated with the proper distribution of resources, the existence of infrastructures, and the balanced physical environment. The present study aimed to survey the indexes of health equity in the physical environment and infrastructures of Kermanshah province based on the national indexes. RESULTS: The results revealed that access to transportation, health centers, solid waste management, and green and sports per capita had the least distance from the negative ideal whereas the noise pollution index had the greatest distance. However, house hygiene and air pollution indexes were within the negative and positive ideal ranges. CONCLUSIONS: The health equity indexes were not distributed equitably across counties and geographical regions of Kermanshah province.

Spatial modeling of mortality from acute lower respiratory infections in children under 5 years of age in 2000-2017: a global study.

BACKGROUND: Over the past few decades, various goals have been defined to reduce the mortality of children caused by acute lower respiratory infections (ALRIs) worldwide. However, few spatial studies to date have reported on ALRI deaths. PURPOSE: We aimed to assess the spatial modeling of mortality from ALRI in children under 5 years of age during 2000-2017 using a global data. METHODS: The data on the mortality of children under 5 years old caused by ALRI were initially obtained from the official website of the World Health Organization. The income status of their home countries was also gathered from the Country Income Groups (World Bank Classification) website and divided into 5 categories. After that, in the ArcGIS 10.6 environment, a database was created and the statistical tests and related maps were extracted. The Global Moran's I statistic, Getis-Ord Gi statistic, and geographically weighted regression were used for the analyses. In this study, higher z scores indicated the hot spots, while lower z scores indicated the cold spots. RESULTS: In 2000-2017, child mortality showed a downward trend from 17.6 per 100,000 children to 8.1 and had a clustered pattern. Hot spots were concentrated in Asia in 2000 but shifted toward African countries by 2017. A cold spot that formed in Europe in 2007 showed an ascending trend by 2017. Based on the results of geographically weighted regression test, the regions identified as the hot spots of mortality from ALRI in children under 5 years old were among the middle-income countries (R2=0.01, adjusted R2=8.77). CONCLUSION: While the total number of child deaths in 2000-2017 has decreased, the number of hot spots has increased among countries. This study also concluded that, during the study period, Central and Western Africa countries became the main new hot spots of deaths from ALRI.

Learning receptive field properties of complex cells in V1.

There are two distinct classes of cells in the primary visual cortex (V1): simple cells and complex cells. One defining feature of complex cells is their spatial phase invariance; they respond strongly to oriented grating stimuli with a preferred orientation but with a wide range of spatial phases. A classical model of complete spatial phase invariance in complex cells is the energy model, in which the responses are the sum of the squared outputs of two linear spatially phase-shifted filters. However, recent experimental studies have shown that complex cells have a diverse range of spatial phase invariance and only a subset can be characterized by the energy model. While several models have been proposed to explain how complex cells could learn to be selective to orientation but invariant to spatial phase, most existing models overlook many biologically important details. We propose a biologically plausible model for complex cells that learns to pool inputs from simple cells based on the presentation of natural scene stimuli. The model is a three-layer network with rate-based neurons that describes the activities of LGN cells (layer 1), V1 simple cells (layer 2), and V1 complex cells (layer 3). The first two layers implement a recently proposed simple cell model that is biologically plausible and accounts for many experimental phenomena. The neural dynamics of the complex cells is modeled as the integration of simple cells inputs along with response normalization. Connections between LGN and simple cells are learned using Hebbian and anti-Hebbian plasticity. Connections between simple and complex cells are learned using a modified version of the Bienenstock, Cooper, and Munro (BCM) rule. Our results demonstrate that the learning rule can describe a diversity of complex cells, similar to those observed experimentally.

Quality of life of HIV-infected individuals: insights from a study of patients in Kermanshah, Iran.

BACKGROUND: Quality of life (QOL) is one of the major factors to assessing the health and wellbeing of People living with HIV (PLWH). Likewise, improved QOL is among the prominent goals of patient treatment. This study was conducted to investigate the QOL of PLWH in Kermanshah, Iran. METHODS: This cross-sectional study was conducted on 364 PLWH of Kermanshah between 2016 and 2017. Outpatients were selected as the sample through the convenience sampling method from HIV Positive Clients of Kermanshah Behavioral Diseases Counseling Center. The reasons for the selection of outpatients include: (a) some patients were substance users, homeless or did not have a fixed address to follow-up; (b) addresses and personal details that were registered on the first admission were incorrect or incomplete; (c) due to financial issues, some were forced to relocate frequently and were difficult to track; (d) some patients were convicts or prisoners, making it hard to find them after their release; (e) some of them were from other provinces, where managing access was not easy/possible. Data was collected using WHOQOL-HIV BREF questionnaire (Persian Version). Data also analyzed with STATA 14, and SPSS 23 using T-test and multiple regression. RESULTS: This study showed that mean (SD) age of PLWH was 40.21 (10.45) years. Females had better QOL than males except for spirituality, religion and personal beliefs. The gender differences disappeared in multivariate results. A significant association was observed between education and the independence, environment, and spirituality domains of QOL. In addition, being married was correlated with overall QOL, psychological and social relationships domains of QOL of PLWH. Drug use was a behavioral factor with negative influence on the QOL. CONCLUSION: This study found that marital status and drug use were the main predictors of various domains of QOL. Drug use was a behavioral factor with a negative influence on the QOL. Hence, it is recommended that health professionals, planners, and policymakers take effective measures to improve the status quo.

Analysis of extracellular spike waveforms and associated receptive fields of neurons in cat primary visual cortex.

KEY POINTS: Extracellular spikes recorded in the visual cortex (Area 17/18, V1) are commonly classified into either regular-spiking (RS) or fast-spiking (FS). Using multi-electrode arrays positioned in cat V1 and a broadband stimulus, we show that there is also a distinct class with positive-spiking (PS) waveforms. PS units were associated mainly with non-oriented receptive fields while RS and FS units had orientation-selective receptive fields. We suggest that PS units are recordings of axons originating from the thalamus. This conclusion was reinforced by our finding that we could record PS units after cortical silencing, but not record RS and FS units. The importance of our findings is that we were able to correlate spike shapes with receptive field characteristics with high precision using multi-electrode extracellular recording techniques. This allows considerable increases in the amount of information that can be extracted from future cortical experiments. ABSTRACT: Extracellular spike waveforms from recordings in the visual cortex have been classified into either regular-spiking (RS) or fast-spiking (FS) units. While both these types of spike waveforms are negative-dominant, we show that there are also distinct classes of spike waveforms in visual Area 17/18 (V1) of anaesthetised cats with positive-dominant waveforms, which are not regularly reported. The spatial receptive fields (RFs) of these different spike waveform types were estimated, which objectively revealed the existence of oriented and non-oriented RFs. We found that units with positive-dominant spikes, which have been associated with recordings from axons in the literature, had mostly non-oriented RFs (84%), which are similar to the centre-surround RFs observed in the dorsal lateral geniculate nucleus (dLGN). Thus, we hypothesise that these positive-dominant waveforms may be recordings from dLGN afferents. We recorded from V1 before and after the application of muscimol (a cortical silencer) and found that the positive-dominant spikes (PS) remained while the RS and FS cells did not. We also noted that the PS units had spiking characteristics normally associated with dLGN units (i.e. higher response spike rates, lower response latencies and higher proportion of burst spikes). Our findings show quantitatively that it is possible to correlate the RF properties of cortical neurons with particular spike waveforms. This has implications for how extracellular recordings should be interpreted and complex experiments can now be contemplated that would have been very challenging previously, such as assessing the feedforward connectivity between brain areas in the same location of cortical tissue.

Photocatalytic degradation of cephalexin by UV activated persulfate and Fenton in synthetic wastewater: optimization, kinetic study, reaction pathway and intermediate products.

We used Low pressure mercury vapor lamp activated of Sodium Persulfate (UV/SPS) and Fenton processes in two separate reactors to comparison of cephalexin (CPX) degradation in aqueous solution. The effect of pH, initial concentration of SPS, concentration of CPX, concentration of H2O2 and concentration of Fe2+ on the degradation of CPX were investigated. The residue of CPX and metabolites were determined by HPLC and GC/MS. The Total Organic Carbon (TOC) analysis was utilized for surveying the mineralization of CPX. Biodegradability of CPX in both advanced oxidation processes was evaluated by BOD5/COD in optimum condition. The results indicated that the maximum CPX removal was obtained at pH 3, H2O2 3 mM, concentration of initial CPX 10 mg/L and by increasing the doses of SPS from 0.1 to 0.2 mM, the degradation of CPX was enhanced. In this study, the most important factors for AOP efficiency was concentration of initial CPX; and then pH in UV/SPS and H2O2 in Fenton processes. The TOC measurements indicate that the UV/SPS and Fenton can efficiently mineralize CPX. CPX removed enough to achieve suitable biodegradability for a further biological process. Too, analysis of generated intermediates during the degradation of CPX was conducted by GC/MS method and a degradation pathway was proposed.