Calorimetry, activity, and micro-FTIR analysis of CO chemisorption, titration, and oxidation on supported Pt

The value of in situ analysis on CO chemisorption, titration and oxidation over supported Pt catalysts using calorimetry, catalytic and micro-FTIR methods is illustrated using silica- and titania-supported samples. Isothermal CO-O and O2-CO titrations have not been widely used on metal surfaces and may be complicated if some oxide supports are reduced by CO titrant. However, they can illuminate the kinetics of CO oxidation on metal/oxide catalysts since during such titrations all O and CO coverages are scanned as a function of time. There are clear advantages in following the rates of the catalyzed CO oxidation via calorimetry and gc-ms simultaneously. At lower temperatures the evidence they provide is complementary. CO oxidation and its catalysis of CO oxidation have been extensively studied with hysteresis and oscillations apparent, and the present results suggest the benefits of a combined approach. Silica support porosity may be important in defining activity-temperature hysteresis. FTIR microspectroscopy reveals the chemical heterogeneity of the catalytic surfaces used; it is interesting that the evidence with regard to the dominant CO surface species and their reactivities with regard to surface oxygen for present oxide-supported Pt are different from those seen on graphite-supported Pt

Changes in Poultry Handling Behavior and Poultry Mortality Reporting among Rural Cambodians in Areas Affected by HPAI/H5N1

BACKGROUND: Since 2004, 21 highly pathogenic avian influenza H5N1 outbreaks in domestic poultry and eight human cases have been confirmed in Cambodia. As a result, a large number of avian influenza education campaigns have been ongoing in provinces in which H5N1outbreaks have occurred in humans and/or domestic poultry. METHODOLOGY/PRINCIPAL FINDINGS: Data were collected from 1,252 adults >15 years old living in two southern provinces in Cambodia where H5N1 has been confirmed in domestic poultry and human populations using two cross-sectional surveys conducted in January 2006 and in November/December 2007. Poultry handling behaviors, poultry mortality occurrence and self-reported notification of suspect H5N1 poultry cases to animal health officials in these two surveys were evaluated. Our results demonstrate that although some at risk practices have declined since the first study, risky contact with poultry is still frequent. Improved rates of reporting poultry mortality were observed overall, but reporting to trained village animal health workers decreased by approximately 50%. CONCLUSIONS/SIGNIFICANCE: Although some improvements in human behavior have occurred, there are still areas--particularly with respect to the handling of poultry among children and the proper treatment of poultry and the surrounding household environment--that need to be addressed in public health campaigns. Though there were some differences in the sampling methods of the 2006 and 2007 surveys, our results illustrate the potential to induce considerable, potentially very relevant, behavioral changes over a short period of time

Factors Associated with Chemical Pesticide use among Farmers in Eastern Part of Cambodia

BACKGROUND: Chemical pesticides are known to have adverse impact on human health. However, little is known about the magnitude and factors influencing chemical pesticide use in Cambodia. The study aimed to describe and determine factors influencing chemical pesticide use among farmers in the Eastern part of Cambodia. SUBJECT AND METHODS: This was a cross-sectional study. A total of 287 farmers were selected by multistage random sampling proportional to size of the population from 8 communes in the Eastern part of Cambodia. The questionnaire was developed to measure variables under study. A multiple logistic regression was applied to estimate the factors influencing chemical pesticide use. RESULTS: 53.66% of the sample was female. Mean age= 41.01, and SD= 10.8 years old. The average monthly income was 460,000 Riel (112 US$). The illiteracy rate was 15.68%. All of these farmers planted rice, cassava and caisim. 72.13% of all farmers used chemical pesticide. 68.13% of 182 rice farmers used 2,4-D. 92.48% of 133 cassava farmers used glyphosate, and 54.89% used 2,4-D. 71.43% of 35 caisim farmers used fipronil, and 68.57% used malathion. Factors significantly associated with chemical pesticide use were illiteracy (OR= 2.60; 95% CI= 1.02 to 6.62; p= 0.045) and increase in farm size per m2 (OR= 2.12; 95% CI= 1.59 to 2.84; p<0.001). CONCLUSION: Chemical pesticide use was very high in Cambodia. Some used prohibited chemical. Illiteracy and farm size affect chemical pesticide use among farmers in Cambodia. Keywords: chemical pesticide use, Cambodia, farme

Socio-demographic and lifestyle factors associated with understanding fast food consumption among adults in Cambodia

Background: Over the past decades, fast food has been rapidly gaining popularity and availability worldwide. Its consequential impact on human health is among the highest in terms of non-communicable diseases. Therefore, this study aimed to investigate the level of understanding of fast food consumption among adults in Phnom Penh, the capital city of Cambodia.Methods: A cross-sectional analytical study aimed to investigate the level of understanding of factors associated with fast food consumption, among adults in Phnom Penh. Multi-stage random sampling was used to select 749 respondents from 12 communes of five districts in Phnom Penh. A structured questionnaire was used to assess the level of understanding of fast food consumption, and associated factors. Data were analyzed using descriptive statistics, together with bivariate and multivariable logistic regression. Crude odds ratios (CORs) and adjusted odds ratios (AORs) with 95% confident intervals (CI) were calculated to show the strength of associations.Results: The understanding of factors associated with fast food consumption was poor in 52.07% (95% CI: 48.48-55.66), fair in 22.70% (95% CI: 19.69-25.70) and good in 25.23% (95% CI: 22.12-28.35) of those surveyed. After adjusting for other covariates, unsatisfactory levels of knowledge around fast food consumption were found to be significantly associated with not taking regular exercise (AOR = 1.53; 95% CI: 1.15-2.25;

Early corn stand count of different cropping systems using UAV-imagery and deep learning

Optimum plant stand density and uniformity is vital in order to maximize corn (Zea mays L.) yield potential. Assessment of stand density can occur shortly after seedlings begin to emerge, allowing for timely replant decisions. The conventional methods for evaluating an early plant stand rely on manual measurement and visual observation, which are time consuming, subjective because of the small sampling areas used, and unable to capture field-scale spatial variability. This study aimed to evaluate the feasibility of an unmanned aerial vehicle (UAV)-based imaging system for estimating early corn stand count in three cropping systems (CS) with different tillage and crop rotation practices. A UAV equipped with an on-board RGB camera was used to collect imagery of corn seedlings (~14 days after planting) of CS, i.e., minimum-till corn-soybean rotation (MTCS), no-till corn-soybean rotation (NTCS), and no-till corn-corn rotation with cover crop implementation (NTCC). An image processing workflow based on a deep learning (DL) model, U-Net, was developed for plant segmentation and stand count estimation. Results showed that the DL model performed best in segmenting seedlings in MTCS, followed by NTCS and NTCC. Similarly, accuracy for stand count estimation was highest in MTCS (R2 = 0.95), followed by NTCS (0.94) and NTCC (0.92). Differences by CS were related to amount and distribution of soil surface residue cover, with increasing residue generally reducing the performance of the proposed method in stand count estimation. Thus, the feasibility of using UAV imagery and DL modeling for estimating early corn stand count is qualified influenced by soil and crop management practices

Complex Ashtekar variables and reality conditions for Holst's action

From the Holst action in terms of complex valued Ashtekar variables additional reality conditions mimicking the linear simplicity constraints of spin foam gravity are found. In quantum theory with the results of You and Rovelli we are able to implement these constraints weakly, that is in the sense of Gupta and Bleuler. The resulting kinematical Hilbert space matches the original one of loop quantum gravity, that is for real valued Ashtekar connection. Our result perfectly fit with recent developments of Rovelli and Speziale concerning Lorentz covariance within spin-form gravity.Comment: 24 pages, 2 picture

Rabies Situation in Cambodia

In Cambodia, rabies still elicits fear in the communities. Since 1998 the Institut Pasteur in Cambodia (IPC), Phnom Penh has been the only source of free post-exposure prophylaxis (PEP) and post mortem diagnosis. During 1998–2007, on average ∼12,400 patients received PEP annually at IPC (range 8,907–14,475) and 63 fatal human cases presenting with encephalitis following a dog bite were reported including 73% who tested positive by fluorescent-antibody test on brain samples or/and by reverse-transcriptase polymerase chain reaction on skin, cerebrospinal fluid, or urine. In 2007, 14,475 patients received PEP (100 PEP/100,000 people in Cambodia) including 95% who resided in Phnom Penh city (615 PEP/100,000) or five neighboring provinces. Using a step-by-step probability model, we estimated that 810 human rabies deaths would occur in 2007 (95% confidence interval [CI] 394–1,607); an incidence of 5.8/100,000 (95%CI 2.8–11.5). As a result, despite high attendance at the IPC's PEP center most Cambodians living in peripheral provinces in Cambodia may not have adequate access to PEP. Finally, the model generated one of the highest incidences of rabies worldwide. A national rabies control program is needed to improve surveillance and access to PEP, and to initiate vaccination campaigns in dogs

Association between socioeconomic factors and soft drink consumption among adults in Cambodia: a cross-sectional study

Background: Soft drinks are an attractive and popular drink, consumed by many people to fulfill their energy. However, soft drink consumption is an important risk factor for non-communicable diseases. This study aimed to investigate the association between socioeconomic factors and soft drink consumption among adults in Cambodia. Methods: A cross-sectional analytical study with multi-stage random sampling was used to select 749 respondents from 12 communes across 5 districts in Phnom Penh, the capital city of Cambodia. A structured questionnaire was used to assess socioeconomic factors and soft drink consumption. Data were analyzed using bivariate and multivariable logistic regression. Crude odds ratios and adjusted odds ratios (AORs) with 95% confident intervals (CI) were calculated to show the strength of associations.Results: The overall prevalence of soft drink consumption was 44.73% (95%CI: 41.16-48.30%) across the sample population. The final model of multiple logistic regression showed only four factors to be significantly associated with soft drink consumption: gender, age, family size and income. Respondents most likely to consume soft drinks were men (AOR: 1.49, 95%CI: 1.10-2.00; p=0.009), those aged 31-59 years (AOR: 1.93, 95%CI: 1.98-4.62; p<0.001), those in a household of less than 5 individuals (AOR: 1.38, 95%CI: 1.44-3.19; p=0.036), and those earning <300$/month (AOR: 1.59, 95%CI: 1.10-2.31; p=0.003).Conclusion: The prevalence of soft drink consumption in Cambodia is a major concern for public health. The predictive factors significantly associated with soft drink consumption identified by this study were gender, age, household size and income. Therefore, all stakeholders should contribute to social marketing and intervention focusing on reducing the consumption of soft drinks through advertising on social media, television and other popular media platforms. Furthermore, additional taxation of soft drinks should be considered

Promoter keyholes enable specific and persistent multi-gene expression programs in primary T cells without genome modification

Non-invasive epigenome editing is a promising strategy for engineering gene expression programs, yet potency, specificity, and persistence remain challenging. Here we show that effective epigenome editing is gated at single-base precision via 'keyhole' sites in endogenous regulatory DNA. Synthetic repressors targeting promoter keyholes can ablate gene expression in up to 99% of primary cells with single-gene specificity and can seamlessly repress multiple genes in combination. Transient exposure of primary T cells to keyhole repressors confers mitotically heritable silencing that persists to the limit of primary cultures in vitro and for at least 4 weeks in vivo, enabling manufacturing of cell products with enhanced therapeutic efficacy. DNA recognition and effector domains can be encoded as separate proteins that reassemble at keyhole sites and function with the same efficiency as single chain effectors, enabling gated control and rapid screening for novel functional domains that modulate endogenous gene expression patterns. Our results provide a powerful and exponentially flexible system for programming gene expression and therapeutic cell products