A meta-analysis of microbial thermal inactivation in low moisture foods.

Microbial thermal inactivation in low moisture foods is challenging due to enhanced thermal resistance of microbes and low thermal conductivity of food matrices. In this study, we leveraged the body of previous work on this topic to model key experimental features that determine microbial thermal inactivation in low moisture foods. We identified 27 studies which contained 782 mean D-values and developed linear mixed-effect models to assess the effect of microorganism type, matrix structure and composition, water activity, temperature, and inoculation and recovery methods on cell death kinetics. Intraclass correlation statistics (I2) and conditional R2 values of the linear mixed effects models were: E. coli (R2-0.91, I2-83%), fungi (R2-0.88, I2-85%), L. monocytogenes (R2-0.84, I2-75%), Salmonella (R2-0.69, I2-46%). Finally, global response surface models (RSM) were developed to further study the non-linear effect of aw and temperature on inactivation. The fit of these models varied by organisms from R2 0.88 (E. coli) to 0.35 (fungi). Further dividing the Salmonella data into individual RSM models based on matrix structure improved model fit to R2 0.90 (paste-like products) and 0.48 (powder-like products). This indicates a negative relationship between data diversity and model performance.

Ultrasonographic criteria in the diagnosis of polycystic ovary syndrome: a systematic review and diagnostic meta-analysis.

BACKGROUND: Polycystic ovary morphology (PCOM) on ultrasonography is considered as a cardinal feature of polycystic ovarian syndrome (PCOS). Its relevance as a diagnostic criterion for PCOS was reaffirmed in the most recent International Evidence-Based Guideline for the Assessment and Management of PCOS. However, there remains a lack of clarity regarding the best practices and specific ultrasonographic markers to define PCOM. OBJECTIVE AND RATIONALE: The aim of this systematic review and diagnostic meta-analysis was to assess the diagnostic accuracy of various ultrasonographic features of ovarian morphology in the diagnosis of PCOS. SEARCH METHODS: Relevant studies published from 1 January 1990 to 12 June 2023 were identified by a systematic search in PubMed, Web of Science, Scopus, CINAHL, and CENTRAL. Studies that generated diagnostic accuracy measures (e.g. proposed thresholds, sensitivity, specificity) for PCOS using the following ultrasonographic markers met criteria for inclusion: follicle number per ovary (FNPO) or per single cross-section (FNPS), ovarian volume (OV), and stromal features. Studies on pregnant or post-menopausal women were excluded. Risk of bias and applicability assessment for diagnostic test accuracy studies were determined using the QUADAS-2 and QUADAS-C tool for a single index test or between multiple index tests, respectively. Diagnostic meta-analysis was conducted using a bivariate model of pooled sensitivity and specificity, and visualized using forest plots and summary receiver-operating characteristic (SROC) curves. OUTCOMES: From a total of 2197 records initially identified, 31 studies were included. Data from five and two studies were excluded from the meta-analysis due to duplicate study populations or limited data for the index test, leaving 24 studies. Pooled results of 20 adult studies consisted of 3883 control participants and 3859 individuals with PCOS. FNPO was the most accurate diagnostic marker (sensitivity: 84%, CI: 81-87%; specificity: 91%, CI: 86-94%; AUC: 0.905) in adult women. OV and FNPS had similar pooled sensitivities (OV: 81%, CI: 76-86%; FNPS: 81%, CI: 70-89%) but inferior pooled specificities (OV: 81%, CI: 75-86%; FNPS: 83%, CI: 75-88%) and AUCs (OV: 0.856; FNPS: 0.870) compared to FNPO. Pooled results from four adolescent studies consisting of 210 control participants and 268 girls with PCOS suggested that OV may be a robust ultrasonographic marker for PCOS diagnosis albeit the current evidence remains limited. The majority of the studies had high risk of bias for the patient selection (e.g. lack of randomized/consecutive patient selection) and index test (e.g. lack of pre-proposed thresholds for comparison) domains across all ultrasonographic markers. As such, diagnostic meta-analysis was unable to determine the most accurate cutoff for ultrasonographic markers to diagnose PCOS. Subgroup analysis suggested that stratification based on previously proposed diagnostic thresholds, age, BMI, or technology did not account for the heterogeneity in diagnostic accuracy observed across the studies. Studies that diagnosed PCOS using the Rotterdam criteria had improved sensitivity for FNPO. Studies from North America had lower diagnostic accuracy when compared to Asian studies (FNPO: sensitivity) and European studies (OV: specificity, diagnostic odds ratio and positive likelihood ratio). Geographic differences in diagnostic accuracy may potentially be due to differences in age, BMI, and diagnostic criteria of the PCOS group across regions. WIDER IMPLICATIONS: This diagnostic meta-analysis supports the use of FNPO as the gold standard in the ultrasonographic diagnosis of PCOS in adult women. OV and FNPS provide alternatives if total antral follicle counts cannot be accurately obtained. Our findings support the potential for ultrasonographic evidence of PCOM in adolescents as more data becomes available. Subgroup analysis suggests the need to investigate any relative contributions of geographical differences on PCOS phenotypes. These findings may provide the basis for the development of strategies and best practices toward a standardized definition of PCOM and a more accurate ultrasonographic evaluation of PCOS.

Gut microbial features and dietary fiber intake predict gut microbiota response to resistant starch supplementation.

Resistant starch (RS) consumption can have beneficial effects on human health, but the response, in terms of effects on the gut microbiota and host physiology, varies between individuals. Factors predicting the response to RS are not yet established and would be useful for developing precision nutrition approaches that maximize the benefits of dietary fiber intake. We sought to identify predictors of gut microbiota response to RS supplementation. We enrolled 76 healthy adults into a seven-week crossover study. Participants consumed RS type 2 (RS2), RS type 4 (RS4), and a digestible starch, for ten days each with five-day washout periods in between. We collected fecal and saliva samples and food records before and during each treatment period. We performed 16S rRNA gene sequencing and measured fecal short-chain fatty acids (SCFAs), salivary amylase gene copy number, and salivary amylase activity (SAA). Dietary fiber intake was predictive of relative abundance of several amplicon sequence variants (ASVs) at the end of both RS treatments. Treatment order (the order of consumption of RS2 and RS4), alpha diversity, and a subset of ASVs were predictive of SCFA changes after RS supplementation. SAA was only predictive of the relative abundance of ASVs after digestible starch supplementation. Based on our findings, dietary fiber intake and gut microbiome composition would be informative if assessed prior to recommending RS supplementation. Using a precision nutrition approach to optimize the benefits of dietary fibers such as RS could be an effective strategy to compensate for the low consumption of dietary fiber nationwide.

Biomineralogical signatures of breast microcalcifications.

Microcalcifications, primarily biogenic apatite, occur in cancerous and benign breast pathologies and are key mammographic indicators. Outside the clinic, numerous microcalcification compositional metrics (e.g., carbonate and metal content) are linked to malignancy, yet microcalcification formation is dependent on microenvironmental conditions, which are notoriously heterogeneous in breast cancer. We interrogate multiscale heterogeneity in 93 calcifications from 21 breast cancer patients using an omics-inspired approach: For each microcalcification, we define a "biomineralogical signature" combining metrics derived from Raman microscopy and energy-dispersive spectroscopy. We observe that (i) calcifications cluster into physiologically relevant groups reflecting tissue type and local malignancy; (ii) carbonate content exhibits substantial intratumor heterogeneity; (iii) trace metals including zinc, iron, and aluminum are enhanced in malignant-localized calcifications; and (iv) the lipid-to-protein ratio within calcifications is lower in patients with poor composite outcome, suggesting that there is potential clinical value in expanding research on calcification diagnostic metrics to include "mineral-entrapped" organic matrix.

Moderate evidence for heritability in the duet contributions of a South American primate.

Acoustic signals are ubiquitous across mammalian taxa. They serve a myriad of functions related to the formation and maintenance of social bonds and can provide conspecifics information about caller condition, motivation and identity. Disentangling the relative importance of evolutionary mechanisms that shape vocal variation is difficult, and little is known about heritability of mammalian vocalizations. Duetting--coordinated vocalizations within male and female pairs--arose independently at least four times across the Primate Order. Primate duets contain individual- or pair-level signatures, but the mechanisms that shape this variation remain unclear. Here, we test for evidence of heritability in two call types (pulses and chirps) from the duets of captive coppery titi monkeys (Plecturocebus cupreus). We extracted four features--note rate, duration, minimum and maximum fundamental frequency--from spectrograms of pulses and chirps, and estimated heritability of the features. We also tested whether features varied with sex or body weight. We found evidence for moderate heritability in one of the features examined (chirp note rate), whereas inter-individual variance was the most important source of variance for the rest of the features. We did not find evidence for sex differences in any of the features, but we did find that body weight and fundamental frequency of chirp elements covaried. Kin recognition has been invoked as a possible explanation for heritability or kin signatures in mammalian vocalizations. Although the function of primate duets remains a topic of debate, the presence of moderate heritability in titi monkey chirp elements indicates duets may serve a kin recognition function.

Sexual selection theory meets disease vector control: Testing harmonic convergence as a "good genes" signal in Aedes aegypti mosquitoes.

BACKGROUND: The mosquito Aedes aegypti is a medically important, globally distributed vector of the viruses that cause dengue, yellow fever, chikungunya, and Zika. Although reproduction and mate choice are key components of vector population dynamics and control, our understanding of the mechanisms of sexual selection in mosquitoes remains poor. In "good genes" models of sexual selection, females use male cues as an indicator of both mate and offspring genetic quality. Recent studies in Ae. aegypti provide evidence that male wingbeats may signal aspects of offspring quality and performance during mate selection in a process known as harmonic convergence. However, the extent to which harmonic convergence may signal overall inherent quality of mates and their offspring remains unknown. METHODOLOGY/PRINCIPAL FINDINGS: To examine this, we measured the relationship between acoustic signaling and a broad panel of parent and offspring fitness traits in two generations of field-derived Ae. aegypti originating from dengue-endemic field sites in Thailand. Our data show that in this population of mosquitoes, harmonic convergence does not signal male fertility, female fecundity, or male flight performance traits, which despite displaying robust variability in both parents and their offspring were only weakly heritable. CONCLUSIONS/SIGNIFICANCE: Together, our findings suggest that vector reproductive control programs should treat harmonic convergence as an indicator of some, but not all aspects of inherent quality, and that sexual selection likely affects Ae. aegypti in a trait-, population-, and environment-dependent manner.

Human Salivary Amylase Gene Copy Number Impacts Oral and Gut Microbiomes.

Host genetic variation influences microbiome composition. While studies have focused on associations between the gut microbiome and specific alleles, gene copy number (CN) also varies. We relate microbiome diversity to CN variation of the AMY1 locus, which encodes salivary amylase, facilitating starch digestion. After imputing AMY1-CN for ∼1,000 subjects, we identified taxa differentiating fecal microbiomes of high and low AMY1-CN hosts. In a month-long diet intervention study, we show that diet standardization drove gut microbiome convergence, and AMY1-CN correlated with oral and gut microbiome composition and function. The microbiomes of low-AMY1-CN subjects had enhanced capacity to break down complex carbohydrates. High-AMY1-CN subjects had higher levels of salivary Porphyromonas; their gut microbiota had increased abundance of resistant starch-degrading microbes, produced higher levels of short-chain fatty acids, and drove higher adiposity when transferred to germ-free mice. This study establishes AMY1-CN as a genetic factor associated with microbiome composition and function.

First Field Release of a Genetically Engineered, Self-Limiting Agricultural Pest Insect: Evaluating Its Potential for Future Crop Protection.

Alternative, biologically-based approaches for pest management are sorely needed and one approach is to use genetically engineered insects. Herein we describe a series of integrated field, laboratory and modeling studies with the diamondback moth, Plutella xylostella, a serious global pest of crucifers. A "self-limiting" strain of Plutella xylostella (OX4319L), genetically engineered to allow the production of male-only cohorts of moths for field releases, was developed as a novel approach to protect crucifer crops. Wild-type females that mate with these self-limiting males will not produce viable female progeny. Our previous greenhouse studies demonstrated that releases of OX4319L males lead to suppression of the target pest population and dilution of insecticide-resistance genes. We report results of the first open-field release of a non-irradiated, genetically engineered self-limiting strain of an agricultural pest insect. In a series of mark-release-recapture field studies with co-releases of adult OX4319L males and wild-type counterparts, the dispersal, persistence and field survival of each strain were measured in a 2.83 ha cabbage field. In most cases, no differences were detected in these parameters. Overall, 97.8% of the wild-type males and 95.4% of the OX4319L males recaptured dispersed <35 m from the release point. The predicted persistence did not differ between strains regardless of release rate. With 95% confidence, 75% of OX4319L males released at a rate of 1,500 could be expected to live between 3.5 and 5.4 days and 95% of these males could be expected to be detected within 25.8-34.9 m from the release point. Moth strain had no effect on field survival but release rate did. Collectively, these results suggest similar field behavior of OX4319L males compared to its wild-type counterpart. Laboratory studies revealed no differences in mating competitiveness or intrinsic growth rates between the strains and small differences in longevity. Using results from these studies, mathematical models were developed that indicate release of OX4319L males should offer efficacious pest management of P. xylostella. Further field studies are recommended to demonstrate the potential for this self-limiting P. xylostella to provide pest suppression and resistance management benefits, as was previously demonstrated in greenhouse studies.

Distribution and population structure of endobacteria in arbuscular mycorrhizal fungi at North Atlantic dunes.

Arbuscular mycorrhizal fungi (AMF, Glomeromycotina), in addition to forming symbioses with the majority of land plants, harbor vertically transmitted endosymbiotic bacteria 'Candidatus Glomeribacter gigasporarum' (CaGg) and 'Candidatus Moeniiplasma glomeromycotorum' (CaMg). CaGg is a nonessential mutualist of AMF, whereas the lifestyle of CaMg is unknown. To start unraveling the interactions between AMF and their endosymbionts in nature, we examined diversity and distribution of AMF-associated endobacteria in North Atlantic dunes at Cape Cod. Of nearly 500 foredune AMF isolates successfully genotyped during a systematic study, 94% were classified as Gigasporaceae. Two percent of all AMF spores harbored CaGg, and 88% contained CaMg. CaGg was found only in the Gigasporaceae, whereas CaMg was present in Gigasporaceae, Acaulosporaceae, and Diversisporaceae. Incidence of CaGg across AMF was not affected by any of the environmental parameters measured, whereas distribution of CaMg in one of the fungal hosts was impacted by plant density. CaMg populations associated with AMF individuals displayed high levels of genetic diversity but no evidence of gene flow, suggesting that host physical proximity is not sufficient to facilitate horizontal transmission of CaMg. Finally, in addition to a novel lineage of CaGg, we discovered that AMF likely harbor Burkholderia-related bacteria with close phylogenetic affinity to free-living Burkholderia and endobacteria of other Mucoromycota fungi.

Performance-Based Financing Empowers Health Workers Delivering Prevention of Vertical Transmission of HIV Services and Decreases Desire to Leave in Mozambique.

BACKGROUND: Despite increased access to treatment and reduced incidence, vertical transmission of HIV continues to pose a risk to maternal and child health in sub-Saharan Africa. Performance-based financing (PBF) directed at healthcare providers has shown potential to improve quantity and quality of maternal and child health services. However, the ways in which these PBF initiatives lead to improved service delivery are still under investigation. METHODS: Therefore, we implemented a longitudinal-controlled proof-of-concept PBF intervention at health facilities and with community-based associations focused on preventing vertical transmission of HIV (PVT) in rural Mozambique. We hypothesized that PBF would increase worker motivation and other aspects of the workplace environment in order to achieve service delivery goals. In this paper, we present two objectives from the PBF intervention with public health facilities (n=6): first, we describe the implementation of the PBF intervention and second, we assess the impact of the PBF on health worker motivation, key factors in the workplace environment, health worker satisfaction, and thoughts of leaving. Implementation (objective 1) was evaluated through quantitative service delivery data and multiple forms of qualitative data (eg, quarterly meetings, participant observation (n=120), exit interviews (n=11)). The impact of PBF on intermediary constructs (objective 2) was evaluated using these qualitative data and quantitative surveys of health workers (n=83) at intervention baseline, midline, and endline. RESULTS: We found that implementation was challenged by administrative barriers, delayed disbursement of incentives, and poor timing of evaluation relative to incentive disbursement (objective 1). Although we did not find an impact on the motivation constructs measured, PBF increased collegial support and worker empowerment, and, in a time of transitioning implementing partners, decreased against desire to leave (objective 2). CONCLUSION: Areas for future research include incentivizing meaningful quality- and process-based performance indicators and evaluating how PBF affects the pathway to service delivery, including interactions between motivation and workplace environment factors.

Potential for subsets of wt-NPM1 primary AML blasts to respond to retinoic acid treatment.

Acute myeloid leukemia (AML) has high mortality rates, perhaps reflecting a lack of understanding of the molecular diversity in various subtypes and a lack of known actionable targets. There are currently 12 open clinical trials for AML using combination therapeutic modalities including all-trans retinoic acid (RA). Mutant nucleophosmin-1, proposed as a possible marker for RA response, is the criterion for recruiting patients in three active RA phase 3 clinical trials. We tested the ability of RA alone or in combination with either bosutinib (B) or 6-formylindolo(3,2-b) carbazole (F) to induce conversion of 12 de novo AML samples toward a more differentiated phenotype. We assessed levels of expression of cell surface markers associated with differentiation, aldehyde dehydrogenase activity, and glucose uptake activity. Colony formation capacity was reduced with the combined treatment of RA and B or F, and correlated with modulation of a c-Cbl/Lyn/c-Raf-centered signalsome. Combination treatment was in most cases more effective than RA alone. Based on their responses to the treatments, some primary leukemic samples cluster closer to HL-60 cells than to other primary samples, suggesting that they may represent a hitherto undefined AML subtype that is potentially responsive to RA in a combination differentiation therapy.

A smoothing expectation and substitution algorithm for the semiparametric accelerated failure time frailty model.

This paper proposes an estimation procedure for the semiparametric accelerated failure time frailty model that combines smoothing with an Expectation and Maximization-like algorithm for estimating equations. The resulting algorithm permits simultaneous estimation of the regression parameter, the baseline cumulative hazard, and the parameter indexing a general frailty distribution. We develop novel moment-based estimators for the frailty parameter, including a generalized method of moments estimator. Standard error estimates for all parameters are easily obtained using a randomly weighted bootstrap procedure. For the commonly used gamma frailty distribution, the proposed algorithm is very easy to implement using widely available numerical methods. Simulation results demonstrate that the algorithm performs very well in this setting. We re-analyz several previously analyzed data sets for illustrative purposes.

Induced smoothing for the semiparametric accelerated failure time model: asymptotics and extensions to clustered data.

This paper extends the induced smoothing procedure of Brown & Wang (2006) for the semiparametric accelerated failure time model to the case of clustered failure time data. The resulting procedure permits fast and accurate computation of regression parameter estimates and standard errors using simple and widely available numerical methods, such as the Newton-Raphson algorithm. The regression parameter estimates are shown to be strongly consistent and asymptotically normal; in addition, we prove that the asymptotic distribution of the smoothed estimator coincides with that obtained without the use of smoothing. This establishes a key claim of Brown & Wang (2006) for the case of independent failure time data and also extends such results to the case of clustered data. Simulation results show that these smoothed estimates perform as well as those obtained using the best available methods at a fraction of the computational cost.