Miracle-dz/UniFAR-FTUs huggingface dataset:
Aflatoxin M1 in raw and imported powdered milk sold in Khartoum state, Sudan

The aim of this study is to determine the level of contamination of aflatoxin M1 (AFM1) in raw and imported powdered milk in Khartoum state, Sudan. Thirty-five samples of fresh cow milk were collected from different farms, based on the source of concentrated feed introduced to the dairy cows (locally vs. commercially produced) and the size of the farm (≤50 vs. >50 cows/farm). Also 12 samples of powdered milk were obtained from repacking companies in Khartoum state. The samples were analysed by a fluorometer, using the Vicam method. AFM1 was detected in all raw and powdered milk samples. Almost 50% of the contaminated powdered milk samples and all the raw milk samples exceeded the European Union limit of 0.05 µg/kg whereas 33% of the contaminated powdered milk samples and 77% of the raw milk samples exceeded the limit of Codex regulations (0.5 µg/kg). The results revealed that the concentration of AFM1 is affected significantly (P < 0.05) by the source of concentrated feed (locally produced or purchased) but not by the farm size. It was concluded that the levels of AFM1 in the milk samples indicated that the feeds offered to the cows were contaminated with aflatoxin B1 to such a level that it might cause a serious health problem to the public. Therefore, there is a need to limit the exposure to aflatoxin by imposing regulatory limits, as well as further studies on large scale bases are needed to investigate the amount of AFM1 in milk and dairy products.
Flap quality in single versus multiple use of the same blade in the Flapmaker microkeratome.

PURPOSE We evaluated experimentally the variability of cut thickness, flap diameter, and cut quality produced by the Flapmaker corneal microkeratome (IOLTech), with single and repeated use of the same cutting blade. METHODS Keratectomy was performed with twelve cutting heads (8.5-mm diameter, 160-microm cutting depth) on 47 corneas and with six cutting heads (8.0-mm diameter, 180-microm cutting depth) on 18 freshly enucleated swine eyes in a repeated manner. Ultrasonic pachymetry was determined at the initial, central, and final microkeratome pass zones, first before the flap was created and subsequently after the flap was reflected. Flap diameter was measured by planimetry. After the procedure stromal portions were submitted for scanning electron microscopy. RESULTS On the first blade use, mean central flap thickness was 145 +/- 32 microm and mean vertical flap diameter was 8.4 +/- 0.26 mm with the 8.5-mm blades. With the 8.0-mm blades, mean central flap thickness was 155 +/- 23 microm and mean vertical flap diameter was 8.0 +/- 0.27 mm. Scanning electron microscopy disclosed smooth cut surfaces when new blades were used, but with repeated blade use, increasingly prominent stromal bed folds were observed. CONCLUSIONS The evaluated blades produced reproducible flap size and thickness and good cut quality with single use, but after the first use, cut quality markedly deteriorated. Repeated use of Flapmaker cutting blades is not recommended.
Modal noise BER calculations in 10-Gb/s multimode fiber LAN links

In this letter, we explore the modal noise penalty dependence on the laser launch conditions. We present calculations that are using the actual launch conditions of the laser, and the actual fiber transfer function, instead of making approximations to the calculation of the standard deviation of the modal noise. The results suggest that in 10-Gb/s multimode local area network links and for laser launches of interest, the laser encircled flux should be limited to 18 /spl mu/m at 1300 nm and 19 /spl mu/m at 850 nm. This would result in no links exceeding their allocation of modal noise penalty in the link power budget. These encircled flux values are in compliance with the requirements for sources used with OM3 fiber.
Characterization of the toxicological hazards of hydrocarbon solvents

Abstract Hydrocarbon solvents are liquid hydrocarbon fractions derived from petroleum processing streams, containing only carbon and hydrogen atoms, with carbon numbers ranging from approximately C5–C20 and boiling between approximately 35–370°C. Many of the hydrocarbon solvents have complex and variable compositions with constituents of 4 types, alkanes (normal paraffins, isoparaffins, and cycloparaffins) and aromatics (primarily alkylated one- and two-ring species). Because of the compositional complexity, hydrocarbon solvents are now identified by a nomenclature (“the naming convention”) that describes them in terms of physical/chemical properties and compositional elements. Despite the compositional complexity, most hydrocarbon solvent constituents have similar toxicological properties, and the overall toxicological hazards can be characterized in generic terms. To facilitate hazard characterization, the solvents were divided into 9 groups (categories) of substances with similar physical and chemical properties. Hydrocarbon solvents can cause chemical pneumonitis if aspirated into the lung, and those that are volatile can cause acute CNS effects and/or ocular and respiratory irritation at exposure levels exceeding occupational recommendations. Otherwise, there are few toxicologically important effects. The exceptions, n-hexane and naphthalene, have unique toxicological properties, and those solvents containing constituents for which classification is required under the Globally Harmonized System (GHS) are differentiated by the substance names. Toxicological information from studies of representative substances was used to fulfill REACH registration requirements and to satisfy the needs of the OECD High Production Volume (HPV) initiative. As shown in the examples provided, the hazard characterization data can be used for hazard classification and for occupational exposure limit recommendations.
Mammalian and Viral IL-10 Enhance C-C Chemokine Receptor 5 but Down-Regulate C-C Chemokine Receptor 7 Expression by Myeloid Dendritic Cells: Impact on Chemotactic Responses and In Vivo Homing Ability1

The immunosuppressive and anti-inflammatory cytokine IL-10 inhibits the phenotypic and functional maturation of dendritic cells (DC) and has been reported to confer tolerogenic properties on these important professional APC. Here, we exposed murine bone marrow-derived myeloid DC to either mouse (m) or viral (v) IL-10 early during their in vitro generation in response to GM-CSF and IL-4. Both mIL-10 and vIL-10 down-regulated the expression of CCR7 mRNA determined by RT-PCR, while mIL-10 up-regulated the expression of CCR5 transcripts. These changes in CCR7 and CCR5 expression were associated with inhibition and augmentation, respectively, of DC chemotaxis toward their respective agonists, macrophage inflammatory proteins 3β and 1α, while in vivo homing of DC from peripheral s.c. sites to secondary lymphoid tissue of syngeneic or allogeneic recipients was significantly impaired. Anti-mIL-10R mAb reversed the effects of mIL-10 on CCR expression and restored DC homing ability. Retroviral transduction of mIL-10- and vIL-10-treated DC to overexpress transgenic CCR7 partially restored the cells’ lymphoid tissue homing ability in allogeneic recipients. However, CCR7 gene transfer did not reinstate the capacity of IL-10-treated DC to prime host naive T cells for ex vivo proliferative responses or Th1 cytokine (IFN-γ) production in response to rechallenge with (donor) alloantigen. These findings suggest that in addition to their capacity to subvert DC maturation/function and confer tolerogenic potential on these cells, mIL-10 and vIL-10 regulate DC migratory responses via modulation of CCR expression.
An anti-Ras cancer potential of PP1, an inhibitor specific for Src family kinases: in vitro and in vivo studies.

BACKGROUND We previously found that both PAK, a Rac/CDC42-activated Ser/Thr kinase, and its binding partner PIX are required for malignant transformation caused by oncogenic Ras mutants, such as v-Ha-Ras. Furthermore, oncogenic Ras requires an autocrine pathway to activate PAK. This pathway involves at least two distinct receptor kinases: EGF receptor (ErbB1) and ErbB2. Interestingly, both of these kinases are known to activate Src family kinases that phosphorylate CAT, another binding partner of PIX. PURPOSE The major aim of this study was to determine whether Src family kinases are required for both Ras-induced PAK activation and malignant transformation. For this purpose, we used PP1, an inhibitor specific for Src family kinases, which does not inhibit either EGF receptor or ErbB2. METHODS AND RESULTS We studied the effect of PP1 on the anchorage-dependent growth of normal and v-Ha-Ras transformed NIH 3T3 fibroblasts, PAK activation and anchorage-independent growth of Ras transformants, and development of Ras-induced sarcomas in nude mice. We found that PP1 (10 nM) strongly inhibits PAK activity in Ras transformants. PP1 at this concentration is known to inhibit c-Fyn kinase, but not c-Src kinase, and none of the three known Src family kinases (c-Src, c-Fyn, and c-Yes) expressed in fibroblasts is activated by v-Ha-Ras. Thus, it is most likely that the primary target of this drug is an as yet unidentified Ras-activated Tyr (Y) kinase or kinases, which we call "Ray. " Although PP1 has no effect on their anchorage-dependent growth, it significantly inhibits their anchorage-independent growth in soft agar, as well as a rapid growth of Ras-induced sarcomas in mice. CONCLUSION Like EGF receptor and ErbB2, a member of Src family kinases (most likely a new Src-related kinase called "Ray") is essential for the Ras-induced activation of PAK and the malignant transformation both in vitro and in vivo. These findings suggest that PP1 and other inhibitors specific for Src family kinases are potentially useful for the treatment of Ras-associated cancers.
Learning to reproduce stochastic time series using stochastic LSTM

Recurrent neural networks (RNNs) have been widely used for complex data modeling. However, when it comes to long-term time-dependent complex sequential data modeling with stochasticities, RNNs seem to fail because of vanishing gradients problem. Hence, in this paper, we propose a new architecture, stochastic long short term memory (S-LSTM), along with its forward and backward dynamics equations. S-LSTM models stochasticities using Bayesian brain hypothesis, which is a probabilistic model that makes predictions against which samples are tested to update the conclusions about their causes. This is the same as minimizing the difference between inference and posterior densities for suppressing the free energy. During training of S-LSTM, it predicts the mean as well as variance at each time step. The prediction error is minimized by the predicted variance which acts as an inverse weighting factor for prediction error and tries to optimize the maximum likelihood. Our proposed model is evaluated through numerical experiments on noisy Lissajous curves. In the experiments, S-LSTM is found to predict and preserve more stochasticities in the noisy Lissajous curves as compared to LSTM.
Effects of mechanical and thermal load cycling on micro tensile bond strength of clearfil SE bond to superficial dentin

Background: Certain studies have been conducted on the effects of mechanical and thermal load cycling on the microtensile bond strength (microTBS) of composites to dentin, but the results were different. The authors therefore decided to evaluate these effects on the bonding of Clearfil SE bond to superficial dentin. Materials and Methods: Flat dentinal surface of 42 molar teeth were bonded to Filtek-Z250 resin composite by Clearfil SE bond. The teeth were randomly divided into 7 groups and exposed to different mechanical and thermal load cycling. Thermocycling was at 5-55°C and mechanical load cycling was created with a force of 125 N and 0.5 Hz. Then, the teeth were sectioned and shaped to hour glass form and subjected to microTBS testing at a speed of 0.5 mm/min. The results were statistically analyzed by computer with three-way analysis of variance and T-test at P < 0.05 significant. To evaluate the location and mode of failure, the specimens were observed under the stereomicroscope. Then, one of the specimens in each group was evaluated under Scanning Electron Microscopy (SEM) for mode of failure. Results: All of the study groups had a significantly lower microTBS as compared to the control group (P < 0.001). There was no statistically significant difference between mechanical cycling with 50K (kilo = 1000) cycles, and 50K mechanical cycles plus 1K thermal cycles. Most of the fractures in the control group were of adhesive type and this type of fracture increased after exposure to mechanical and thermal load cycling. Conclusion: Thermal and mechanical load cycling had significant negative effects on microTBS and the significant effects of mechanical load cycling started to be significant at 100K cycles.
Does a CEO’s Cultural Heritage Affect Performance Under Competitive Pressure?

We exploit variation in the cultural heritage across U.S. CEOs who are the children or grandchildren of immigrants to demonstrate that the cultural origins of CEOs matter for corporate outcomes. Following shocks to industry competition, firms led by CEOs who are second- or third-generation immigrants are associated with a 6.2% higher profitability compared with the average firm. This effect weakens over successive immigrant generations and cannot be detected for top executives apart from the CEO. Additional analysis attributes this effect to various cultural values that prevail in a CEO’s ancestral country of origin.
Requiring Help Injecting Independently Predicts Incident HIV Infection Among Injection Drug Users

Background:Requiring help injecting has been associated with syringe sharing among injection drug users (IDUs). No prospective study has fully examined this risk factor and its relation to rates of HIV infection. We investigated whether requiring help injecting illicit drugs was a predictor of HIV infection among a prospective cohort of IDUs. Methods:The Vancouver Injection Drug User Study is a prospective study of more than 1500 IDUs who have been recruited from the Downtown Eastside of Vancouver since May 1996. At baseline and semiannually, subjects provided blood samples and completed an interviewer-administered questionnaire. The questionnaire elicits demographic data as well as information about drug use, HIV risk behavior, and drug treatment. HIV incidence rates were calculated using Kaplan-Meier methods, and Cox regression determined independent predictors of seroconversion. Results:A total of 1013 baseline HIV-negative participants were eligible for this study. Within this population, 418 (41.3%) participants had required help injecting during the last 6 months at baseline. Participants requiring help injecting were more likely to be female (odds ratio = 2.3, 95% confidence interval [CI]: 1.8-3.0; P < 0.001), were slightly younger (33.5 vs. 34.9 years of age; P = 0.014), and had fewer years of experience injecting drugs (7 vs. 11 years; P ≤ 0.001). Among participants who required help injecting at baseline, cumulative HIV incidence at 36 months was 16.1% compared with 8.8% among participants who did not require help injecting (log-rank, P < 0.001). In an adjusted model controlling for potential confounding variables, being aboriginal (relative hazard [RH] = 1.68, 95% CI: 1.15-2.48), injecting cocaine daily (RH = 2.71, 95% CI: 1.87-3.95), and requiring help injecting (RH = 1.79, 95% CI: 1.23-2.62) remained independent predictors of HIV seroconversion. Conclusions:These data demonstrate the need for interventions to reduce the risk of HIV infection among IDUs who require help injecting.
Quantification of Histone H3 Lys27 Trimethylation (H3K27me3) by High-Throughput Microscopy Enables Cellular Large-Scale Screening for Small-Molecule EZH2 Inhibitors

EZH2 inhibition can decrease global histone H3 lysine 27 trimethylation (H3K27me3) and thereby reactivates silenced tumor suppressor genes. Inhibition of EZH2 is regarded as an option for therapeutic cancer intervention. To identify novel small-molecule (SMOL) inhibitors of EZH2 in drug discovery, trustworthy cellular assays amenable for phenotypic high-throughput screening (HTS) are crucial. We describe a reliable approach that quantifies changes in global levels of histone modification marks using high-content analysis (HCA). The approach was validated in different cell lines by using small interfering RNA and SMOL inhibitors. By automation and miniaturization from a 384-well to 1536-well plate, we demonstrated its utility in conducting phenotypic HTS campaigns and assessing structure-activity relationships (SAR). This assay enables screening of SMOL EZH2 inhibitors and can advance the mechanistic understanding of H3K27me3 suppression, which is crucial with regard to epigenetic therapy. We observed that a decrease in global H3K27me3, induced by EZH2 inhibition, comprises two distinct mechanisms: (1) inhibition of de novo DNA methylation and (II) inhibition of dynamic, replication-independent H3K27me3 turnover. This report describes an HCA assay for primary HTS to identify, profile, and optimize cellular active SMOL inhibitors targeting histone methyltransferases, which could benefit epigenetic drug discovery.
Salmonella enterica Burden in Harvest-Ready Cattle Populations from the Southern High Plains of the United States

ABSTRACT Our objectives were to quantify the Salmonella enterica burdens in harvest-ready cattle and to identify specific at-risk populations of cattle most likely to harbor multiply resistant S. enterica. Hide swabs were collected in abattoirs from three cohorts of cattle (feedlot origin cattle that had achieved desirable harvest characteristics and dairy- and beef-type cows harvested because of poor productivity). Feces were collected from two cohorts housed in feedlots (cattle that had achieved desirable harvest characteristics and animals identified for salvage recovery because of poor productivity). Facilities were visited on four occasions over a 12-month period. Salmonella enterica isolates were recovered, and organisms were quantified using standard microbiological methodologies. Susceptibility to antimicrobial drugs and serotype were determined for one S. enterica isolate per sample. Salmonella enterica was recovered from 55.6% of 1,681 samples. The prevalences on hides and in feces were 69.6% and 30.3%, respectively. The concentrations of S. enterica organisms averaged (as determined by the most probable number technique) 1.82 log10/100 cm2 of hides and 0.75 log10/g of feces. None of the isolates recovered from cattle that had achieved desirable harvest characteristics were resistant to four or more drugs. For isolates recovered from animals with poor productivity characteristics, 6.5% were resistant to four or more drugs. Twenty-two serovars were identified, with the most common being Salmonella enterica serovar Anatum (25.5%), Salmonella enterica serovar Montevideo (22.2%), and Salmonella enterica serovar Cerro (12.5%). High-level resistance, i.e., resistance to four or more drugs, was clustered within a few relatively uncommon serovars. These results demonstrate that even though S. enterica isolates are readily recoverable from harvest-ready cattle, multiply resistant variants are rare and are associated with specific serovars in cattle harvested because of poor productivity characteristics.
Myristoylated alanine rich C kinase substrate (MARCKS) heterozygous mutant mice exhibit deficits in hippocampal mossy fiber‐CA3 long‐term potentiation

The myristoylated alanine‐rich C kinase substrate (MARCKS) is a primary protein kinase C (PKC) substrate in brain thought to transduce PKC signaling into alterations in the filamentous (F) actin cytoskeleton. Within the adult hippocampus, MARCKS is highly expressed in the dentate gyrus (DG)‐CA3 mossy fiber pathway, but is expressed at low levels in the CA3‐CA1 Schaffer collateral‐CA1 pathway. We have previously demonstrated that 50% reductions in MARCKS expression in heterozygous Marcks mutant mice produce robust deficits in spatial reversal learning, but not contextual fear conditioning, suggesting that only specific aspects of hippocampal function are impaired by reduction in MARCKS expression. To further elucidate the role of MARCKS in hippocampal synaptic plasticity, in the present study we examined basal synaptic transmission, paired‐pulse facilitation, post‐tetanic potentiation, and long‐term potentiation (LTP) in the hippocampal mossy fiber‐CA3 and Schaffer collateral‐CA1 pathways of heterozygous Marcks mutant and wild‐type mice. We found that LTP is significantly impaired in the mossy fiber‐CA3 pathway, but not in the Schaffer collateral‐CA1 pathway, in heterozygous Marcks mutant mice, whereas basal synaptic transmission, paired‐pulse facilitation, and post‐tetanic potentiation are unaffected in both pathways. These findings indicate that a 50% reduction in MARCKS expression impairs processes required for long‐term, but not short‐term, synaptic plasticity in the mossy fiber‐CA3 pathway. The implications of these findings for the role of the mossy fiber‐CA3 pathway in hippocampus‐dependent learning processes are discussed. © 2006 Wiley‐Liss Inc.
Occupational Exposures Associated with Petroleum-Derived Products Containing Trace Levels of Benzene

Benzene may be present as a trace impurity or residual component of mixed petroleum products due to refining processes. In this article, the authors review the historical benzene content of various petroleum-derived products and characterize the airborne concentrations of benzene associated with the typical handling or use of these products in the United States, based on indoor exposure modeling and industrial hygiene air monitoring data collected since the late 1970s. Analysis showed that products that normally contained less than 0.1% v/v benzene, such as paints and paint solvents, printing solvents and inks, cutting and honing oils, adhesives, mineral spirits and degreasers, and jet fuel typically have yielded time-weighted average (TWA) airborne concentrations of benzene in the breathing zone and surrounding air ranging on average from <0.01 to 0.3 ppm. Except for a limited number of studies where the benzene content of the product was not confirmed to be <0.1% v/v, airborne benzene concentrations were also less than current occupational exposure limits (e.g., threshold limit value of 0.5 ppm and permissible exposure limit of 1.0 ppm) based on exceedance fraction calculations. Exposure modeling using Monte Carlo techniques also predicted 8-hr TWA near field airborne benzene concentrations ranging from 0.002 to 0.4 ppm under three hypothetical solvent use scenarios involving mineral spirits. The overall weight-of-evidence indicates that the vast majority of products manufactured in the United States after about 1978 contained <0.1% v/v benzene, and 8-hr TWA airborne concentrations of benzene in the workplace during the use of these products would not have been expected to exceed 0.5 ppm under most product use scenarios. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a document containing exposure modeling scenarios and results, historical benzene content of petroleum-derived products, and air monitoring results. ]