Border walls and smuggling spillovers

A growing number of states are erecting physical barriers along their borders to stem the illicit flow of goods and people. Though border fortification policies are both controversial and politically salient, their distributional consequences remain largely unexplored. We study the impact of a border wall project on smuggling in Israel. We use the initial phase of the wall construction to causally estimate spillover effects on cross-border smuggling, especially vehicle theft. We find a large decrease in smuggling of stolen vehicles in protected towns and a similar substantial increase in not-yet-protected towns. For some protected towns, fortification also arbitrarily increased the length of smuggling routes. These township-level shocks further deterred smuggling (6% per kilometer). Our findings suggest that border fortification may have uneven distributional consequences, creating unintended winners and losers

Exploring Differences In Decisions About Exams Among Instructors Of The Same Introductory Biology Course

College instructors in the United States usually make their own decisions about how to design course exams. Even though summative course exams are well known to be important to student success, we know little about the decision making of instructors when designing course exams. To probe how instructors design exams for introductory biology, we conducted an exploratory interview study with seven instructors teaching the same introductory biology course at a large university. We found that despite designing exams for the same course, instructor exam decisions differed with regard to what content was assessed, the exam format, the cognitive difficulty of exam questions, the resources used when crafting exams, and how exams were administered. We hope that this work can initiate conversations about how college instructors should design exams and lead to more uniformity in how student learning is assessed across the same courses taught by different instructors

Publication and research trends among neurological residents

Research is a critical aspect of residency training, but many programs lack a robust research component in their curriculum. Research publications are one way that physicians can advance their career in academic medicine, and the number of publications is often used as a criterion for determining suitable fellowship applicants. In this study, we evaluate the relationship between publications during and after residency in the field of neurology as well as analyze the relationship between number of publications and characteristics such as gender and career path. We randomly selected 50 ACGME Neurology residency programs from across the United States and recorded the number of publications, h-index, gender, fellowship choice, and career path for each graduate between 2013-2015. Each publication was sorted into time frames before residency, during residency, and after residency. The study included a total of 379 neurology residents from 25 different residency programs. Residents who pursued academic medicine had a significantly higher mean total publications (M = 10.1, SD 16.4) than those who pursued private practice (M = 4.2, SD 9.0) (t377 =-4.5, p <0.000). The mean total publications for male residents (M = 8.6, SD 16.5) was significantly higher than female residents (M = 4.1, SD 5.6) (t377 =-3.6, p <0.0002). Pearson correlation also revealed a correlation between publications during residency and publications after residency, with a Pearson product moment correlation of 0.61. The positive correlation between number of publications during residency and publications after residency, demonstrates the importance of implementing strong research principles and practice in a residency's curriculum. We also report a higher number of mean total publications by those who pursued academic medicine than those who pursued private practice. In addition, the results show an underrepresentation of females in neurology research, indicating a need to encourage more females to engage in neurology research and possibly STEM fields in general at an earlier stage in their educational career

Microspatial distribution of trace elements in feline dental hard tissues: early life exposure to essential and toxic elements

IntroductionTrace elements play a key role in dental tissue development, as dental hard tissues accumulate both essential and toxic trace elements during mineralization. Characterization of the spatial accumulation pattern of trace elements may provide insight into exposure to toxic elements over time and to the nature of disease processes affecting the hard dental tissues. Here, we present the first report of the use of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to map the microspatial distribution of multiple trace elements, essential and toxic, across feline dental hard tissues.MethodsEleven teeth were extracted from 8 cats. Nine teeth were from 7 cats diagnosed with idiopathic tooth resorption on intraoral radiographs prior to extraction. Two teeth were included from a cadaver that had no signs of tooth resorption on intraoral radiographs. The normal dental tissue was analyzed from each sample using LA-ICP-MS to map the microspatial distribution of essential and toxic trace elements across feline enamel, dentin, and cementum.ResultsResults showed a higher accumulation of barium and strontium in coronal dentin as compared to root dentin. The timing of the accumulation mirrors nursing timelines seen in teeth from human and non-human primates, consistent with barium and strontium being sourced from maternal milk. Results also showed a higher uptake of lead in the coronal dentin, suggesting this lead exposure was likely passed from mother to offspring.DiscussionThis work characterizes a baseline for elemental distribution in feline teeth linked to early life exposure to toxic elements such as lead and provides a framework for future studies investigating long-term environmental exposures to trace elements, essential and toxic, and their involvement in feline systemic and dental diseases

Performance of the Xpert HPV assay in women attending for cervical screening

© 2015 The Authors. Objectives: This study evaluated the Xpert HPV Assay in women attending screening in general practice by comparing Xpert with two established HPV tests, cytology and histology. Methods: A prospective study in women aged 20-60 years attending screening in Bristol, Edinburgh and London using residual Preservcyt cytology samples. Sample order was randomised between Roche cobas4800 and Cepheid Xpert assays with Qiagen hc2 third. Results: 3408 cases were included in the primary analysis. Positivity for Xpert was 19.6%, cobas 19.2% and hc2 19.9% with high concordance (kappa=86.8% vs cobas, 81.55 vs hc2). Xpert, cobas and hc2 showed similar sensitivity (98.7%, 97.5%, 98.7%) for CIN2+. All pairwise comparisons had high concordance (Kappa ≥0.78 with any abnormal cytology. Xpert and hc2 were positive for all cases of ≥moderate dyskaryosis ( N=63)), cobas was negative in two. Histology was available for 172 participants. 79 reported CIN2+, 47 CIN3+. All CIN3+ was positive on Xpert and hc2 and one case negative for cobas. One case of CIN2 was negative for all assays. Conclusions: The performance of Xpert HPV Assay in a general screening population is comparable to established HPV tests. It offers simplicity of testing, flexibility with non-batching of individual samples and rapid turnaround time

The Nuclear Network: Multiplex Network Analysis for Interconnected Systems

States facing the decision to develop a nuclear weapons program do so within a broader context of their relationships with other countries. How these diplomatic, economic, and strategic relationships impact proliferation decisions, however, remains under-specified. Adding to the existing empirical literature that attempts to model state proliferation decisions, this article introduces the first quantitative heterogeneous network analysis of how networks of conflict, alliances, trade, and nuclear cooperation interact to spur or deter nuclear proliferation. Using a multiplex network model, we conceptualize states as nodes linked by different modes of interaction represented on individual network layers. Node strength is used to quantify factors correlated with nuclear proliferation and these are combined in a weighted sum across layers to provide a metric characterizing the proliferation behavior of the state. This multiplex network modeling approach provides a means for identifying states with the highest relative likelihood of proliferation—based only on their relationships to other states. This work demonstrates that latent conflict and nuclear cooperation are positively correlated with proliferation, while an increased trade dependence suggests a decreased proliferation likelihood. A case study on Iran’s controversial nuclear program and past nuclear activity is also provided. These findings have clear, policy-relevant conclusions related to alliance posture, sanctions policy, and nuclear assistance. Abstract ©The Authors

J. L. Austin and literal meaning

Alice Crary has recently developed a radical reading of J. L. Austin's philosophy of language. The central contention of Crary's reading is that Austin gives convincing reasons to reject the idea that sentences have context-invariant literal meaning. While I am in sympathy with Crary about the continuing importance of Austin's work, and I think Crary's reading is deep and interesting, I do not think literal sentence meaning is one of Austin's targets, and the arguments that Crary attributes to Austin or finds Austinian in spirit do not provide convincing reasons to reject literal sentence meaning. In this paper, I challenge Crary's reading of Austin and defend the idea of literal sentence meaning

Bone Mass and Strength are Significantly Improved in Mice Overexpressing Human WNT16 in Osteocytes

Recently, we demonstrated that osteoblast-specific overexpression of human WNT16 increased both cortical and trabecular bone mass and structure in mice. To further identify the cell-specific role of Wnt16 in bone homeostasis, we created transgenic (TG) mice overexpressing human WNT16 in osteocytes using Dmp1 promoter (Dmp1-hWNT16 TG) on C57BL/6 (B6) background. We analyzed bone phenotypes and serum bone biomarkers, performed gene expression analysis and measured dynamic bone histomorphometry in Dmp1-hWNT16 TG and wild-type (WT) mice. Compared to WT mice, Dmp1-hWNT16 TG mice exhibited significantly higher whole-body, spine and femoral aBMD, BMC and trabecular (BV/TV, Tb.N, and Tb.Th) and cortical (bone area and thickness) parameters in both male and female at 12 weeks of age. Femur stiffness and ultimate force were also significantly improved in the Dmp1-hWNT16 TG female mice, compared to sex-matched WT littermates. In addition, female Dmp1-hWNT16 TG mice displayed significantly higher MS/BS, MAR and BFR/BS compared to the WT mice. Gene expression analysis demonstrated significantly higher mRNA level of Alp in both male and female Dmp1-hWNT16 TG mice and significantly higher levels of Osteocalcin, Opg and Rankl in the male Dmp1-hWNT16 TG mice in bone tissue compared to sex-matched WT mice. These results indicate that WNT16 plays a critical role for acquisition of both cortical and trabecular bone mass and strength. Strategies designed to use WNT16 as a target for therapeutic interventions will be valuable to treat osteoporosis and other low bone mass conditions

HELIUM PHOTODISINTEGRATION AND NUCLEOSYNTHESIS: IMPLICATIONS FOR TOPOLOGICAL DEFECTS, HIGH ENERGY COSMIC RAYS, AND MASSIVE BLACK HOLES

We consider the production of $^3$He and $^2$H by $^4$He photodisintegration initiated by non-thermal energy releases during early cosmic epochs. We find that this process cannot be the predominant source of primordial $^2$H since it would result in anomalously high $^3$He/D ratios in conflict with standard chemical evolution assumptions. We apply this fact to constrain topological defect models of highest energy cosmic ray (HECR) production. Such models have been proposed as possible sources of ultrahigh energy particles and gamma-rays with energies above $10^{20}$eV. The constraints on these models derived from $^4$He-photodisintegration are compared to corresponding limits from spectral distortions of the cosmic microwave background radiation (CMBR) and from the observed diffuse gamma-ray background. It is shown that for reasonable primary particle injection spectra superconducting cosmic strings, unlike ordinary strings or annihilating monopoles, cannot produce the HECR flux at the present epoch without violating at least the $^4$He-photodisintegration bound. The constraint from the diffuse gamma-ray background rules out the dominant production of HECR by the decay of Grand Unification particles in models with cosmological evolution assuming standard fragmentation functions. Constraints on massive black hole induced photodisintegration are also discussed.Comment: 20 latex pages, 1 figure added via figures comman