HIV, Tuberculosis, and Food Insecurity in Africa-A Syndemics-Based Scoping Review.

The double burden of HIV/AIDS and tuberculosis (TB), coupled with endemic and problematic food insecurity in Africa, can interact to negatively impact health outcomes, creating a syndemic. For people living with HIV/AIDS (PWH), food insecurity is a significant risk factor for acquiring TB due to the strong nutritional influences and co-occurring contextual barriers. We aim to synthesize evidence on the syndemic relationship between HIV/AIDS and TB co-infection and food insecurity in Africa. We conducted a scoping review of studies in Africa that included co-infected adults and children, with evidence of food insecurity, characterized by insufficient to lack of access to macronutrients. We sourced information from major public health databases. Qualitative, narrative analysis was used to synthesize the data. Of 1072 articles screened, 18 articles discussed the syndemic effect of HIV/AIDS and TB co-infection and food insecurity. Reporting of food insecurity was inconsistent, however, five studies estimated it using a validated scale. Food insecure co-infected adults had an average BMI of 16.5-18.5 kg/m2. Negative outcomes include death (n = 6 studies), depression (n = 1 study), treatment non-adherence, weight loss, wasting, opportunistic infections, TB-related lung diseases, lethargy. Food insecurity was a precursor to co-infection, especially with the onset/increased incidence of TB in PWH. Economic, social, and facility-level factors influenced the negative impact of food insecurity on the health of co-infected individuals. Nutritional support, economic relief, and psychosocial support minimized the harmful effects of food insecurity in HIV-TB populations. Interventions that tackle one or more components of a syndemic interaction can have beneficial effects on health outcomes and experiences of PWH with TB in Africa.

Beretta barrel fired bullet validation study.

A report published in 2016 by the President's Council of Advisors on Science and Technology (PCAST) criticized studies that have been published regarding the discipline of firearm identification. This study was designed to answer some of these criticisms and involved 30 consecutively manufactured Beretta brand 9 mm Luger caliber barrels. This study had an "open set" design to help the discipline of firearm identification establish "Foundational Validity" which is outlined in the PCAST report. Seventy-two qualified firearm examiners completed and submitted answers for this study that included 15 knowns and 20 unknowns. There were an additional 5 firearms with similar characteristics as the Beretta barrels that were also included as unknowns which provided "known non-match" comparisons. Test sets were created using the random function in Microsoft Excel. Collaborative Testing Services (CTS) funded, facilitated, distributed the tests, and collected the answers from qualified firearm examiners throughout the United States and the world. Firearm examiners were able to complete the test of fired bullets with a low error rate. The error rate for the corrected data was 0.08% (1 in 1250) with the lower confidence interval as low as 0.01% (1 in 10,000) and the upper confidence interval being as high as 0.4% (1 in 250).

Isotopic analogs as internal standards for quantitative GC/MS analysis--molecular abundance and retention time difference as interference factors.

The following analyte/isotope-labeled internal standard (IS) systems are adapted to further study the interference phenomenon previously reported from our laboratory--the intensity ratio of the ion-pair designated for a specific analyte/2H-analog system increases as the solvent used to reconstitute the extraction/derivatization residue is increased: (a) Three analyte/2H-analog pairs with 2H-atoms positioned at allylic sites (butalbital, secobarbital, methohexital); (b) Two analyte/2H-analog pairs without these structural features (pentobarbital, phenobarbital); and (c) Two analyte/13C-analog pairs (butalbital, secobarbital). Major experimental parameters adapted in this study include: (a) Varying reconstitution solvent volume while keeping a constant analyte/IS concentration ratio; (b) Varying analyte/IS concentration ratio; (c) Varying gas chromatograph (GC) injection port temperature; and (d) Varying GC column temperature programming conditions, rendering difference in the degree of overlap of the peaks derived from the analyte and the 2H-analog. This study results in the following observations: (a) Changes in the intensity ratio of the ion-pair designated for a specific analyte/2H-analog system depend on molecular abundance, regardless of whether the 2H-atoms are positioned at active allylic positions or not--thus, ruling out hydrogen/deuterium exchange as the cause of the observed interference phenomenon; (b) Variations in GC injection port temperature do not alter the observed interference phenomenon-thus, ruling out chemical reactions at the injection port as the underlying cause; (c) Variations in peak-overlapping between the analyte and the 2H-analog, facilitated by changing GC column programming conditions, alter the observed interference phenomenon. Abundance of the analyte and the 2H-analog and their overlapping characteristic in the mass spectrometer ion source are believed to be the underlying cause of the observed interference phenomenon. The interference phenomenon observed for a specific analyte/2H-analog system has significant consequences on the linearity of the thereby generated calibration curves. Nonlinear approaches can better describe the calibration data and are needed more in comparison to systems in which 13C-analogs are used as the ISs.