Dome Formation During Crustal Extension in the Himalaya: Kinematic and Pressure-Temperature-Time-Deformation Constraints on Extensional Exhumation Along the Southern Margin of the Tibetan Plateau

The Himalaya and Tibetan Plateau were built by a combination of south-directed thrusting, north-directed extension, and generally east-west-directed extension within the Himalaya and Tibetan Plateau all to accommodate convergence between the Indian and Eurasian plates that began in the Eocene. Normal-sense shear zones that accommodate roughly east-west-directed extension across the southern margin of the Himalaya have exhumed young metamorphic domes across the Himalayan front. These metamorphic domes contain high-grade metamorphic rocks bound by normal-sense shear zones. The purpose of this study is to evaluate how these normal-sense shear zones develop and how they exhume metamorphic domes, which remains poorly understood and is critical for understanding the processes that accommodate extensional exhumation in this convergent setting. Two examples of metamorphic domes that were exhumed by east-west-directed normal-sense shear zones in the Himalaya are the Ama Drime Massif, southern Tibet, and the Leo Pargil dome, northwest India-Tibet. The Ama Drime Massif is a 30 km-wide north-south-striking structure that thins toward the north. It is located ~50 km northeast of Mount Everest and is bound by the Nyönno Ri detachment on the eastern flank and the Ama Drime detachment on the western flank. The Leo Pargil dome, ~950 km west of Ama Drime, is a 20 km-wide, northeast-southwest-striking structure composed of high-grade metamorphic rocks and leucogranite. It is bound on the east by the Qusum detachment and on the west by the Leo Pargil shear zone. Field mapping and sample collection were combined with kinematic, microstructural, thermobarometric, and geochronologic methods to constrain the metamorphic conditions, the kinematics of deformation during shearing, the amount of exhumation, and the timing of metamorphism and shear zone initiation. These data demonstrate the exhumation on these normal-sense shear zones in the Himalaya are controlled by an interplay between various processes including a regional kinematic setting that favored extension which led to strain partitioning, fault reactivation, decompression-driven melting, and the development of these deeply-rooted extensional systems

Crustal Thickening, Partial Melting, and Strain Localization: Insights from the Leo Pargil dome, NW India

Abstract HKT-ISTP 2013 A

Evidence for the prepattern/cooption model of vertebrate jaw evolution

The appearance of jaws was a turning point in vertebrate evolution because it allowed primitive vertebrates to capture and process large, motile prey. The vertebrate jaw consists of separate dorsal and ventral skeletal elements connected by a joint. How this structure evolved from the unjointed gill bar of a jawless ancestor is an unresolved question in vertebrate evolution. To understand the developmental bases of this evolutionary transition, we examined the expression of 12 genes involved in vertebrate pharyngeal patterning in the modern jawless fish lamprey. We find nested expression of Dlx genes, as well as combinatorial expression of Msx, Hand and Gsc genes along the dorso-ventral (DV) axis of the lamprey pharynx, indicating gnathostome-type pharyngeal patterning evolved before the appearance of the jaw. In addition, we find that Bapx and Gdf5/6/7, key regulators of joint formation in gnathostomes, are not expressed in the lamprey first arch, whereas Barx, which is absent from the intermediate first arch in gnathostomes, marks this domain in lamprey. Taken together, these data support a new scenario for jaw evolution in which incorporation of Bapx and Gdf5/6/7 into a preexisting DV patterning program drove the evolution of the jaw by altering the identity of intermediate first-arch chondrocytes. We present this “Pre-pattern/Cooption” model as an alternative to current models linking the evolution of the jaw to the de novo appearance of sophisticated pharyngeal DV patterning

The Use of HCG‐Based Combination Therapy for Recovery of Spermatogenesis after Testosterone Use

Introduction and AimAbout 3 million men take testosterone in the United States with many reproductive‐age men unaware of the negative impact of testosterone supplementation on fertility. Addressing this population, we provide an early report on the use of human chorionic gonadotropin (HCG)‐based combination therapy in the treatment of a series of men with likely testosterone‐related azoospermia or severe oligospermia. MethodsWe retrospectively reviewed charts from two tertiary care infertility clinics to identify men presenting with azoospermia or severe oligospermia (<1 million sperm/mL) while taking exogenous testosterone. All were noted to have been placed on combination therapy, which included 3,000 units HCG subcutaneously every other day supplemented with clomiphene citrate, tamoxifen, anastrozole, or recombinant follicle‐stimulating hormone (or combination) according to physician preference.Main Outcome MeasureClinical outcomes, including hormone values, semen analyses, and clinical pregnancies, were tracked. ResultsForty‐nine men were included in this case series. Return of spermatogenesis for azoospermic men or improved counts for men with severe oligospermia was documented in 47 men (95.9%), with one additional man (2.1%) having a documented pregnancy without follow‐up semen analysis. The average time to return of spermatogenesis was 4.6 months with a mean first density of 22.6 million/mL. There was no significant difference in recovery by type of testosterone administered or supplemental therapy. No men stopped HCG or supplemental medications because of adverse events. ConclusionsWe here provide an early report of the feasibility of using combination therapy with HCG and supplemental medications in treating men with testosterone‐related infertility. Future discussion and studies are needed to further characterize this therapeutic approach and document the presumed improved tolerability and speed of recovery compared with unaided withdrawal of exogenous testosterone. Wenker EP, Dupree JM, Langille GM, Kovac J, Ramasamy R, Lamb D, Mills JN, and Lipshultz LI. The use of HCG‐based combination therapy for recovery of spermatogenesis after testosterone use. J Sex Med 2015;12:1334–1337.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111925/1/jsm12890.pd

Simple gene assembly as a rewriting of directed overlap-inclusion graphs

The simple intramolecular model for gene assembly in ciliates consists of three molecular operations, simple Id, simple hi and simple dlad. Mathematical models in terms of signed permutations and signed strings proved limited in capturing some of the combinatorial details of the simple gene assembly process. Brijder and Hoogeboom introduced a new model in terms of overlap-inclusion graphs which could describe two of the three operations of the model and their combinatorial properties. To capture the third operation, we extended their framework to directed overlap-inclusion (DOI) graphs in Azimi et al. (2011) [1]. In this paper we introduce DOI graph-based rewriting rules that capture all three operations of the simple gene assembly model and prove that they are equivalent to the string-based formalization of the model. (C) 2012 Elsevier B.V. All rights reserved

G(alpha)11 signaling through ARF6 regulates F-actin mobilization and GLUT4 glucose transporter translocation to the plasma membrane

The action of insulin to recruit the intracellular GLUT4 glucose transporter to the plasma membrane of 3T3-L1 adipocytes is mimicked by endothelin 1, which signals through trimeric G(alpha)q or G(alpha)11 proteins. Here we report that murine G(alpha)11 is most abundant in fat and that expression of the constitutively active form of G(alpha)11 [G(alpha)11(Q209L)] in 3T3-L1 adipocytes causes recruitment of GLUT4 to the plasma membrane and stimulation of 2-deoxyglucose uptake. In contrast to the action of insulin on GLUT4, the effects of endothelin 1 and G(alpha)11 were not inhibited by the phosphatidylinositol 3-kinase inhibitor wortmannin at 100 nM. Signaling by insulin, endothelin 1, or G(alpha)11(Q209L) also mobilized cortical F-actin in cultured adipocytes. Importantly, GLUT4 translocation caused by all three agents was blocked upon disassembly of F-actin by latrunculin B, suggesting that the F-actin polymerization caused by these agents may be required for their effects on GLUT4. Remarkably, expression of a dominant inhibitory form of the actin-regulatory GTPase ARF6 [ARF6(T27N)] in cultured adipocytes selectively inhibited both F-actin formation and GLUT4 translocation in response to endothelin 1 but not insulin. These data indicate that ARF6 is a required downstream element in endothelin 1 signaling through G(alpha)11 to regulate cortical actin and GLUT4 translocation in cultured adipocytes, while insulin action involves different signaling pathways

New Cryogenian, Neoproterozoic, and middle Paleozoic U–Pb zircon ages from the Caledonia terrane, southern New Brunswick, Canada: better constrained but more complex volcanic stratigraphy

New U–Pb zircon ages from volcanic, plutonic, and sedimentary units in the Avalonian Caledonia terrane of southern New Brunswick provide better timing constraints in this geologically complex area. Previous ca. 620 Ma ages from the Broad River Group are now corroborated by additional dates from felsic tuff in the Gordon Falls Formation and rhyolite in the former Fairfield (now East Branch Black River) Formation of 620 ± 5 Ma and 622 ± 1.9 Ma, respectively. Combined with ages ranging from ca. 625 Ma to 615 Ma from crosscutting plutons, the data suggest that the minimum age of the Broad River Group is about 615 Ma. A quartzfeldspar porphyry dyke in mafic volcanic rocks of the previously undated Long Beach Formation yielded an igneous crystallization age of 685 ± 10 Ma, the oldest unit yet dated in the Caledonia terrane but similar in age to porphyry in the Stirling belt in the Avalonian Mira terrane of Nova Scotia. The age of the Coldbrook Group was constrained previously by U–Pb (zircon) ages of volcanic rocks between 560 and 550 Ma as well as by similar ages from comagmatic plutons. Five additional samples from both volcanic and plutonic units lie in the same range of 560–550 Ma, including errors, demonstrating that the Coldbrook Group and related plutons formed in less than 10 million years. Such a large volume of mainly felsic magma erupted and emplaced in a short time span suggests a “supereruption/supervolcano” environment such as the late Cenozoic southwestern USA but not yet recognized at ca. 560–550 Ma elsewhere in Avalonia. Two units yielded Paleozoic ages: felsite of the Bloomsbury Mountain Formation with a zircon population at 427 ± 9 Ma, indicating a Silurian maximum emplacement age, and dacite of the Grassy Lake Formation with several zircon grains at 382.8 ± 8.3 Ma, indicating a maximum age of middle Devonian, the first rocks of this age to be identified in the Caledonia terrane

MicrobeDB: a locally maintainable database of microbial genomic sequences

Summary: Analysis of microbial genomes often requires the general organization and comparison of tens to thousands of genomes both from public repositories and unpublished sources. MicrobeDB provides a foundation for such projects by the automation of downloading published, completed bacterial and archaeal genomes from key sources, parsing annotations of all genomes (both public and private) into a local database, and allowing interaction with the database through an easy to use programming interface. MicrobeDB creates a simple to use, easy to maintain, centralized local resource for various large-scale comparative genomic analyses and a back-end for future microbial application design

An online study combining the constructs from the theory of planned behaviour and protection motivation theory in predicting intention to test for chlamydia in two testing contexts

Chlamydia is a common sexually-transmitted infection that has potentially serious consequences unless detected and treated early. The health service in the UK offers clinic-based testing for chlamydia but uptake is low. Identifying the predictors of testing behaviours may inform interventions to increase uptake. Self-tests for chlamydia may facilitate testing and treatment in people who avoid clinic-based testing. Self-testing and being tested by a health care professional (HCP) involve two contrasting contexts that may influence testing behaviour. However, little is known about how predictors of behaviour differ as a function of context. In this study, theoretical models of behaviour were used to assess factors that may predict intention to test in two different contexts: self-testing and being tested by a HCP. Individuals searching for, or reading about chlamydia testing online were recruited using Google Adwords. Participants completed an online questionnaire that addressed previous testing behaviour and measured constructs of the Theory of Planned Behaviour and Protection Motivation Theory, which propose a total of eight possible predictors of intention. The questionnaire was completed by 310 participants. Sufficient data for multiple regression were provided by 102 and 118 respondents for self-testing and testing by a HCP respectively. Intention to self-test was predicted by vulnerability and self-efficacy, with a trend-level effect for response efficacy. Intention to be tested by a HCP was predicted by vulnerability, attitude and subjective norm. Thus, intentions to carry out two testing behaviours with very similar goals can have different predictors depending on test context. We conclude that interventions to increase self-testing should be based on evidence specifically related to test context