Measurement of single event upsets in the ALICE-TPC front-end electronics

The Time Projection Chamber of the ALICE experiment at the CERN Large Hadron Collider features highly integrated on-detector read-out electronics. It is following the general trend of high energy physics experiments by placing the front-end electronics as close to the detector as possible -- only some 10 cm away from its active volume. Being located close to the beams and the interaction region, the electronics is subject to a moderate radiation load, which allowed us to use commercial off-the-shelf components. However, they needed to be selected and qualified carefully for radiation hardness and means had to be taken to protect their functionality against soft errors, i.e. single event upsets. Here we report on the first measurements of LHC induced radiation effects on ALICE front-end electronics and on how they attest to expectations

Transcription of the human and rodent SPAM1 / PH-20 genes initiates within an ancient endogenous retrovirus

BACKGROUND: Sperm adhesion molecule 1 (SPAM1) is the major mammalian testicular hyaluronidase and is expressed at high levels in sperm cells. SPAM1 protein is important for penetration of the cumulus cell layer surrounding the ovum, and is also involved in zona pellucida binding and sperm intracellular signalling. A previous study had identified SPAM1 as one of the many human genes that initiate within a transposable element. RESULTS: Examination of the human, mouse and rat SPAM1 loci revealed that transcripts initiate within the pol gene of an endogenous retrovirus (ERV) element. This is highly unusual, as all previously identified ERV-initiated cellular gene transcripts initiate within the viral long terminal repeat promoter. The SPAM1 locus therefore represents an example of the evolution of a promoter from protein-coding sequence. We have identified novel alternative promoter and splicing variants of human and murine SPAM1. We show that all transcript variants are expressed primarily in the testis and are predicted to encode identical proteins. CONCLUSION: The testis-specific promoters of the human and mouse SPAM1 genes are derived from sequence that was originally part of an ERV pol gene. This represents the first known example of an ERV-derived promoter acting in a gender-specific manner

H⁺ Permeation and pH Regulation at a Mammalian Serotonin Transporter

The rat serotonin transporter expressed in Xenopusoocytes displays an inward current in the absence of 5-HT when external pH is lowered to 6.5 or below. The new current differs from the leakage current described previously in two ways. (1) It is ∼10-fold larger at pH 5 than the leakage current at pH 7.5 and reaches 1000 H⁺/sec per transporter at extremes of voltage and pH with no signs of saturation. (2) It is selective for H⁺ by reversal potential measurements. Similar H⁺-induced currents are also observed in several other ion-coupled transporters, including the GABA transporter, the dopamine transporter, and the Na⁺/glucose transporter. The high conductance and high selectivity of the H⁺-induced current suggest that protons may be conducted via a hydrogen-bonded chain (a “proton-wire mechanism”) formed at least partially by side chains within the transporter. In addition, pH affects other conducting states of rat serotonin transporter. Acidic pH potentiates the 5-HT-induced, transport-associated current and inhibits the hyperpolarization-activated transient current. The dose–response relationships for these two effects suggest that two H⁺ binding sites, with pK_a values close to 5.1 and close to 6.3, govern the potentiation of the 5-HT-induced current and the inhibition of the transient current, respectively. These results are important for developing structure-function models that explain permeation properties of neurotransmitter transporters

“How do we get to them?” Insights on Preconception and Interconception Health for Women in Rural Northwest Ohio

Background: Rural women in the United States are at increased risk for poor preconception and interconception health. In a previous study, women living in Hardin County, a Primary Care Health Professional Shortage Area and maternity care desert in rural northwest Ohio expressed their concerns and their need for more resources to improve their health. As a follow-up study, key informants of Hardin County were interviewed to provide further insight on current resources for preconception and women’s health available to community members, barriers and challenges community members face, and interventions could be implemented in the county to improve health and pregnancy outcomes. Methods: A purposive sample of 14 key informants from community assets in Hardin County were recruited and individually interviewed with semistructured questions from 2 domains: perceived needs and barriers to care. Interview recordings were transcribed, precoded, and thematically analyzed. Participants received a $20 gift card as a token of appreciation. Results: Three themes were characterized from the data: current resources available, community observations, and suggested intervention strategies. Key informants identified the federally-qualified health center and YMCA, among others, as potentially underutilized resources for reproductive-age women. The small-town culture was described as both an advantage and disadvantage when trying to raise awareness about preconception/interconception health. Interventions built on partnerships and utilizing various outlets were suggested. Childcare, intergenerational knowledge transfer, and trust were issues crossing multiple themes. Conclusion: Key informants gave direction on available resources for reproductive-age women and potential approaches to provide education and outreach regarding preconception/interconception health and care

H⁺ Permeation and pH Regulation at a Mammalian Serotonin Transporter

The rat serotonin transporter expressed in Xenopusoocytes displays an inward current in the absence of 5-HT when external pH is lowered to 6.5 or below. The new current differs from the leakage current described previously in two ways. (1) It is ∼10-fold larger at pH 5 than the leakage current at pH 7.5 and reaches 1000 H⁺/sec per transporter at extremes of voltage and pH with no signs of saturation. (2) It is selective for H⁺ by reversal potential measurements. Similar H⁺-induced currents are also observed in several other ion-coupled transporters, including the GABA transporter, the dopamine transporter, and the Na⁺/glucose transporter. The high conductance and high selectivity of the H⁺-induced current suggest that protons may be conducted via a hydrogen-bonded chain (a “proton-wire mechanism”) formed at least partially by side chains within the transporter. In addition, pH affects other conducting states of rat serotonin transporter. Acidic pH potentiates the 5-HT-induced, transport-associated current and inhibits the hyperpolarization-activated transient current. The dose–response relationships for these two effects suggest that two H⁺ binding sites, with pK_a values close to 5.1 and close to 6.3, govern the potentiation of the 5-HT-induced current and the inhibition of the transient current, respectively. These results are important for developing structure-function models that explain permeation properties of neurotransmitter transporters