Premature rejection in science: The case of the Younger Dryas Impact Hypothesis.

The progress of science has sometimes been unjustifiably delayed by the premature rejection of a hypothesis for which substantial evidence existed and which later achieved consensus. Continental drift, meteorite impact cratering, and anthropogenic global warming are examples from the first half of the twentieth century. This article presents evidence that the Younger Dryas Impact Hypothesis (YDIH) is a twenty-first century case.The hypothesis proposes that the airburst or impact of a comet ∼12,850 years ago caused the ensuing ∼1200-year-long Younger Dryas (YD) cool period and contributed to the extinction of the Pleistocene megafauna in the Western Hemisphere and the disappearance of the Clovis Paleo-Indian culture. Soon after publication, a few scientists reported that they were unable to replicate the critical evidence and the scientific community at large came to reject the hypothesis. By today, however, many independent studies have reproduced that evidence at dozens of YD sites. This article examines why scientists so readily accepted the early false claims of irreproducibility and what lessons the premature rejection of the YDIH holds for science.

Absence of relationship between serum cortisol and critical illness in premature infants.

BACKGROUND: Inadequate cortisol production in response to critical illness in extremely preterm infants may exacerbate poor outcomes. Despite commonly measuring cortisol concentration and administering hydrocortisone for presumed adrenal insufficiency, the relationship between serum cortisol concentration and illness severity remains unclear in this unique population. OBJECTIVE: To determine the relationship between cortisol concentrations and illness severity as measured by the Score for Neonatal Acute Physiology II, neonatal Sequential Organ Failure Assessment and Vasoactive-Inotropic Score in premature infants. DESIGN/METHODS: This retrospective, single-center cohort study included preterm infants born <30 weeks gestational age admitted to a level IV neonatal intensive care unit (NICU) between June 2011 and July 2018, who had a serum cortisol obtained for clinical indications before 36 weeks PMA. Demographic data were collected on infants and mothers. Nine clinical variables were identified a priori that could potentially modify cortisol concentration including critical illness. Univariate and multivariable analyses determined the relationship between cortisol concentration and each of these variables. RESULTS: A total of 224 preterm infants with pretreatment serum cortisol concentration met criteria for inclusion. The median (IQR) gestational age at birth was 25 weeks (24, 26) and at cortisol measurement was 26 weeks (25, 28). The median cortisol was 13.3 ug/dL. Non-survivors had the highest values. Cortisol concentration did not correlate with any of the selected illness severity scores. CONCLUSIONS: Cortisol concentrations in extremely preterm infants did not correlate with illness severity regardless of gestational age. Further studies are needed to identify clinically useful mediators of adrenal dysfunction and to guide clinical management.

Systematic Analysis of the Relative Abundance of Polymers Occurring as Microplastics in Freshwaters and Estuaries.

Despite growing interest in the environmental impact of microplastics, a standardized characterization method is not available. We carried out a systematic analysis of reliable global data detailing the relative abundance of polymers in freshwaters and estuaries. The polymers were identified according to seven main categories: polyethylene terephthalate, polyethylene, polyvinyl chloride, polypropylene, polystyrene, polyurethane and a final category of miscellaneous plastic. The results show that microplastics comprised of polyvinyl chloride and polyurethane are significantly less abundant than would be expected based on global production, possibly due to their use. This has implications for models of microplastic release into the environment based on production and fate. When analysed by matrix (water, sediment or biota) distinct profiles were obtained for each category. Polyethylene, polypropylene and polystyrene were more abundant in sediment than in biota, while miscellaneous plastics was more frequent in biota. The data suggest that environmental sorting of microplastic particles, influenced by physical, chemical and biological processes, may play a key role in environmental impact, although partitioning among matrices based on density was not realized. The distinct profile of microplastics in biota raises an important question regarding potential selectivity in uptake by organisms, highlighting the priority for more and better-informed laboratory exposure studies.

A framework for inferring biological communities from environmental DNA.

Environmental DNA (eDNA), genetic material recovered from an environmental medium such as soil, water, or feces, reflects the membership of the ecological community present in the sampled environment. As such, eDNA is a potentially rich source of data for basic ecology, conservation, and management, because it offers the prospect of quantitatively reconstructing whole ecological communities from easily obtained samples. However, like all sampling methods, eDNA sequencing is subject to methodological limitations that can generate biased descriptions of ecological communities. Here, we demonstrate parallels between eDNA sampling and traditional sampling techniques, and use these parallels to offer a statistical structure for framing the challenges faced by eDNA and for illuminating the gaps in our current knowledge. Although the current state of knowledge on some of these steps precludes a full estimate of biomass for each taxon in a sampled eDNA community, we provide a map that illustrates potential methods for bridging these gaps. Additionally, we use an original data set to estimate the relative abundances of taxon-specific template DNA prior to PCR, given the abundance of DNA sequences recovered post-PCR-and-sequencing, a critical step in the chain of eDNA inference. While we focus on the use of eDNA samples to determine the relative abundance of taxa within a community, our approach also applies to single-taxon applications (including applications using qPCR), studies of diversity, and studies focused on occurrence. By grounding inferences about eDNA community composition in a rigorous statistical framework, and by making these inferences explicit, we hope to improve the inferential potential for the emerging field of community-level eDNA analysis.

Leiomyoma in a Renal Allograft.

Leiomyomas are smooth muscle tumours that are rarely found in the kidney. There is one report of a leiomyoma in a kidney transplant in a paediatric recipient. Here, we report an adult renal transplant recipient who developed an Epstein-Barr virus-positive leiomyoma in his allograft 15 years after transplantation. The patient was converted to everolimus for posttransplant immunosuppression management and there was no sign of progression over a year.

Targeting IL-17A attenuates neonatal sepsis mortality induced by IL-18.

Interleukin (IL)-18 is an important effector of innate and adaptive immunity, but its expression must also be tightly regulated because it can potentiate lethal systemic inflammation and death. Healthy and septic human neonates demonstrate elevated serum concentrations of IL-18 compared with adults. Thus, we determined the contribution of IL-18 to lethality and its mechanism in a murine model of neonatal sepsis. We find that IL-18-null neonatal mice are highly protected from polymicrobial sepsis, whereas replenishing IL-18 increased lethality to sepsis or endotoxemia. Increased lethality depended on IL-1 receptor 1 (IL-1R1) signaling but not adaptive immunity. In genome-wide analyses of blood mRNA from septic human neonates, expression of the IL-17 receptor emerged as a critical regulatory node. Indeed, IL-18 administration in sepsis increased IL-17A production by murine intestinal γδT cells as well as Ly6G(+) myeloid cells, and blocking IL-17A reduced IL-18-potentiated mortality to both neonatal sepsis and endotoxemia. We conclude that IL-17A is a previously unrecognized effector of IL-18-mediated injury in neonatal sepsis and that disruption of the deleterious and tissue-destructive IL-18/IL-1/IL-17A axis represents a novel therapeutic approach to improve outcomes for human neonates with sepsis.

An item analysis of the Conditional Reasoning Test of Aggression.

This manuscript uses item response theory (IRT) to estimate item characteristics of the Conditional Reasoning Test of Aggression (CRT-A). Using a sample size of 5,511 respondents, the present analysis provides an accurate assessment of the capability of the CRT-A to measure latent aggression. The one-parameter logistic (1PL) model, two-parameter logistic (2PL) model, and three-parameter logistic (3PL) model are compared before the item analysis. Results suggest that the 2PL model is the most appropriate dichotomous IRT model for describing the item characteristics of the CRT-A. Potential multdimensionality in the CRT-A is also examined. Results suggest that CRT-A items work as theoretically intended, with the probability of selecting an aggressive response increasing with latent trait levels. Information curves indicate that the CRT-A is best suited for use with individuals who are high on latent aggression. Exploratory analyses include an examination of polytomous IRT models and DIF comparing student and employee respondents. The results have implications for future research using the CRT-A as well as the identification of populations appropriate for measurement using this assessment tool.

StayFuse for proximal interphalangeal joint fusion.

BACKGROUND: Proximal interphalangeal (PIP) joint fusion is a commonly performed procedure for lesser-toe deformities. There are various techniques described to accomplish it. We report the results of PIP joint fusion carried out with an intramedullary fusion device in 150 consecutive toes. The aim of our study was to evaluate the outcomes of PIP joint fusion with this technique. METHOD: A total of 150 toes in 140 consecutive patients who underwent PIP joint fusions of the lesser toes with a StayFuse implant were included in our study. The mean age of the patients was 69.5 years, and the mean follow-up was 18 months. Clinical, radiologic, and subjective evaluations as well as preoperative and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) scores were carried out. RESULTS: Of the PIP joints, 95.3% were clinically asymptomatic, but the radiologic fusion was 73%. The mean preoperative AOFAS score improved from 22.9 to 81.6 at follow-up. There were implant-related complications in 8 toes. Ninety-five percent of the patients were satisfied with the procedure, and 3.3% of the patients needed revision surgery. CONCLUSION: This technique maintained PIP joint alignment and provided rotational and angular stability with high patient satisfaction and low complication and reoperation rates. We conclude that this is a reproducible technique and an alternative for PIP joint fusions. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Bone structure and geometry in young men: the influence of smoking, alcohol intake and physical activity.

BACKGROUND: The development of osteoporosis is influenced by peak bone mass attained in youth - the influence of lifestyle factors upon which is poorly described, especially amongst males. We sought to address this issue in a large scale study. METHODS: Hip bone mineral density (dual X-ray absorptiometry, DXA), bone microarchitecture (calcaneal quantitative ultrasound, QUS) and femoral geometry (magnetic resonance imaging, MRI) were characterised in 723 healthy male military recruits (mean ± S.E. age 19.92 ± 0.09 years [range 16-18 years], height 177.67 ± 0.24 cm, weight 73.17 ± 0.37 kg) on entry to UK Army training. Association was sought with prior physical activity, smoking status and alcohol intake. RESULTS: DXA measures were made in 651, MRI measures in 650, and QUS measures in 572 recruits. Increasing levels of weight-bearing physical activity enhanced periostial bone apposition, increases in both total hip and femoral neck bone mineral density (BMD; p ≤ 0.0001 in both cases), and cortical [p<0.0001] and periostial bone volumes [p=0.016]. Smoking habit was associated with preserved bone geometry, but worse BMD [p=0.0001] and QUS characteristics [p ≤ 0.0005]. Moderate alcohol consumption was associated with greater BMD [p ≤ 0.015]. CONCLUSIONS: Whilst exercise (and perhaps moderate alcohol intake) is beneficial to bone morphometry, smoking is detrimental to bone mineral density in young males notable for the likely short duration of smoking to influence skeletal properties. However, differences in socio-economic status, lifestyle and related environmental factors may to some extent confound our results.

The cognitive underpinnings of addiction.

A new conditional reasoning measure was developed to evaluate the role of implicit biases in perpetuating addictive behavior. Data (N = 669) were collected in 2005 from two samples in a suburban area: individuals with a known history of chemical dependency and individuals from the general population. Results indicated a strong correlation between overall test scores and group membership (r(pb) = .48), which increased when the groups' demographic characteristics were equalized (r(pb) = .65). Overall, findings suggest that addiction-prone individuals rely on a distinct set of cognitive biases that rationalize self-destructive behavior. The study's limitations are noted and implications and directions for future research are discussed.

Preoperative thrombolysis and venoplasty affords no benefit in patency following first rib resection and scalenectomy for subacute and chronic subclavian vein thrombosis.

BACKGROUND: Axillosubclavian vein thrombosis, also known as Paget-Schroetter syndrome, is a rare presentation of thoracic outlet syndrome (TOS) representing approximately 5% of all cases. Conventional management consists of routine anticoagulation, operative decompression via first rib resection and scalenectomy (FRRS), and, recently, thrombolysis. The purpose of our study was to retrospectively review our experience with this condition and compare the effectiveness of preoperative endovascular intervention with thrombolysis and venoplasty to anticoagulation alone in those undergoing FRRS to preserve subclavian vein patency. METHODS: A retrospective review was conducted for all venous TOS patients from July 2003 to May 2009 from a prospectively maintained database. Preoperative clinic notes were reviewed to allow stratification into two groups. One group consisted of patients undergoing preoperative endovascular intervention with thrombolysis and venoplasty, while the other group consisted of patients managed medically with anticoagulation alone prior to FRSS. Operative notes, postoperative venograms, and postoperative duplex imaging results were reviewed for presence of recanalization, chronic nonocclusive thrombus, or continued occlusion. RESULTS: One hundred three patients had 110 FRRS for subclavian vein thrombosis (53 men, 50 women), seven of which had contralateral FRRS for thrombosis. The cohort averaged 31 years of age (range, 16-54 years) with an overall, mean follow-up time of 16 months (range, 1-52 months). Of the 110 veins evaluated, 45 underwent endovascular intervention (thombolysis, with or without venoplasty) prior to FRRS, and at 1 year, 41 (91%) were patent with improvement of symptoms. In the 65 veins on anticoagulation alone, 59 (91%) ultimately were patent, with symptomatic improvement in all. Overall, 91% (100/110) of subclavian veins were patent in patients completing follow-up, were asymptomatic, and back to their previous active lifestyle. CONCLUSIONS: Preoperative endovascular intervention offered no benefit over simple anticoagulation prior to FRRS, since the use of thrombolysis prior to FRRS, regardless of need for postoperative venoplasty, had little impact on overall rates of patency. The optimal treatment algorithm may merely be routine anticoagulation for all effort thrombosis patients prior to FRRS followed by venography with venoplasty if needed. The role of thrombolysis for Paget-Schroetter syndrome should be further investigated in randomized trials.

Effect of time of preparation on pentagastrin-induced symptom, endocrine and cardiovascular responses.

Pentagastrin is a cholecystokinin (CCK)-B agonist and laboratory panicogenic agent that produces endocrine (ACTH and cortisol), symptom (anxiety, panic) and cardiovascular (heart rate) responses. Although in vitro data have supported its chemical stability, preliminary data suggested that increasing time between drug preparation and drug infusion could reduce the magnitude of endocrine and symptom responses. The current study examined this possibility. Twenty-one healthy subjects presented at the University of Michigan General Clinical Research Center (GCRC) and had an intravenous catheter inserted. Heart rate, cortisol levels and subjective anxiety were measured before and after pentagastrin and placebo injections. Pentagastrin was prepared either within 60 min of IV infusion (Normal Preparation group) or at least 3.5 h prior to infusion (Early Preparation group). Relative to the Normal Preparation group, Early Preparation subjects had similar heart rate responses but significantly smaller cortisol and subjective anxiety responses. Early preparation of pentagastrin thus appears to weaken endocrine and subjective anxiety responses, highlighting the importance of attending to often overlooked procedural variables (e.g., time between preparation and administration) in studies of this type. The sensitivity of cortisol and anxiety responses to preparation time, but insensitivity of heart rate, is consistent with previous studies suggesting different thresholds of activation for the three response modalities. These differential sensitivities may suggest different and separable CCK-B stimulated pathways for each response, which combine to produce panic, rather than a single, unified CCK-B mediated panicogenic response.

Implicit and explicit personality: a test of a channeling hypothesis for aggressive behavior.

D. G. Winter, O. P. John, A. J. Stewart, E. C. Klohnen, and L. E. Duncan (1998) proposed that self-beliefs about personality influence the channels through which people express their implicit motives. On the basis of this hypothesis, the authors predicted that self-beliefs about aggressiveness would influence the channel(s) through which people express their aggressive motive and the justification mechanisms they use to defend expression of this motive. For example, the authors predicted that people who were implicitly prepared to rationalize a desire to harm others would engage in (a) overt aggression if they viewed themselves as aggressive or (b) passive aggression if they viewed themselves as nonaggressive. The implicit aspects of aggressiveness were measured via conditional reasoning (L. R. James et al., 2005). Results based on intramural basketball players supported the channeling hypothesis.

An integrative typology of personality assessment for aggression: implications for predicting counterproductive workplace behavior.

This study presents an integrative typology of personality assessment for aggression. In this typology, self-report and conditional reasoning (L. R. James, 1998) methodologies are used to assess 2 separate, yet often congruent, components of aggressive personalities. Specifically, self-report is used to assess explicit components of aggressive tendencies, such as self-perceived aggression, whereas conditional reasoning is used to assess implicit components, in particular, the unconscious biases in reasoning that are used to justify aggressive acts. These 2 separate components are then integrated to form a new theoretical typology of personality assessment for aggression. Empirical tests of the typology were subsequently conducted using data gathered across 3 samples in laboratory and field settings and reveal that explicit and implicit components of aggression can interact in the prediction of counterproductive, deviant, and prosocial behaviors. These empirical tests also reveal that when either the self-report or conditional reasoning methodology is used in isolation, the resulting assessment of aggression may be incomplete. Implications for personnel selection, team composition, and executive coaching are discussed.

Measurement issues associated with conditional reasoning tests: indirect measurement and test faking.

Conditional reasoning is a new measurement technique used to measure cognitive biases associated with latent personality motives. The current article describes 3 studies examining 2 related measurement issues associated with conditional reasoning tests (CRTs). Study 1 examined the necessity of maintaining indirect assessment when administering CRTs. Results indicated that, compared with a control condition, 2 experimental conditions that disclosed the purpose of assessment yielded significant mean shifts on a CRT. Study 2 explored whether CRTs could be faked when the purpose of assessment was not disclosed. Results indicated that when indirect measurement was maintained, CRTs appeared to be resistant to faking. Study 3 compared scores on the Conditional Reasoning Test for Aggression across student, applicant, and incumbent samples. Results indicated no significant mean differences among these samples.

Comparison of visual immunoassay and chromogenic culture medium for the presence of Listeria spp. in foods.

Two rapid screening methods [the TECRA Listeria Visual Immunoassay (LIS-VIS) kit, an AOAC-approved 48 h visual test, which detects Listeria through colorimetry, and BCM Listeria isolation and differentiation plating agar] were used to screen U.S. Food and Drug Administration-regulated commodities for the presence of Listeria spp. Seventy-four different food samples were screened for the presence of Listeria spp. by using both protocols. Test results for the TECRA LIS-VIA showed 66 negative samples and 1 false positive, with 4 confirmed as L. monocytogenes and 3 as L. innocua. With the BCM agar, 67 samples were negative, 4 were confirmed as L. monocytogenes, and 3 were confirmed as L. innocua. Both methods showed similar results and were effective screening tools for Listeria spp. in foods. The BCM agar method proved to be a rapid, sensitive, and excellent tool for early screening and differentiation of Listeria spp. present in foods.

Neutralizing substitutes for leadership theory: leadership effects and common-source bias.

The purpose of this research was to examine alternative models of substitutes for leadership theory given the general lack of empirical support for the moderating effects postulated by the theory. On this basis, the research posited that the effects of substitutes also could be conceptualized as mediated relations. The research examined moderated and mediated relations for several sets of leader behaviors and substitutes that have been examined in the literature. The research design sampled 49 organizations, with 940 subordinates rating 156 leaders. Results, although generally not supportive of the moderator or mediator hypotheses, essentially demonstrated that leadership matters. The findings also suggest that prior significant effects in substitutes literature may be merely a statistical artifact, resulting from common-source bias.

A comparative analysis of glove permeation resistance to paint stripping formulations.

Although there is a wide variety of work gloves available to users of commercial paint stripping products, there are no published studies examining which type of gloves provide the best protection. To address this need, a multiphase study was undertaken to evaluate how several types of gloves resist multichemical-based paint stripping formulations. Due to the wide range of commercial paint stripping formulations available, seven categories of surrogate paint stripper formulations were created to evaluate glove performance initially. Twenty different glove types were identified for initial evaluation. Degradation resistance screening was carried out for each glove style and paint stripping formulation. Screening results were used to identify those glove styles least affected by the surrogate paint strippers. Those gloves were then evaluated for their resistance to permeation using continuous contact testing based on ASTM Test Method F 739. Glove styles showing extensive permeation with early breakthrough were then evaluated to see how they performed with only intermittent contact with the surrogate paint strippers using a modified form of ASTM Test Method F 1383. These results were used to select glove styles to be tested using commercially available paint stripping products. Gloves made of plastic laminate and butyl rubber were the most effective against the majority of paint strippers. More glove styles resisted permeation by N-methylpyrrolidone and dibasic ester-based paint strippers than conventional solvent products such as methylene chloride, methanol, isopropanol, acetone, and toluene. The study also found that decreased contact time caused relatively little change in permeation resistance and that the surrogate paint stripper data did not always accurately predict resistance to the commercial paint stripper formulations.