193 research outputs found

    Clinical Presentation and Conservative Management of Tympanic Membrane Perforation during Intrapartum Valsalva Maneuver

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    Background. Tympanic membrane perforation may occur when ear pressures are excessive, including valsalva maneuver associated with active labor and vaginal delivery. A pressure differential across the eardrum of about 5 psi can cause rupture; the increased intraabdominal pressure spikes repeatedly manifested by “pushing” during second-stage labor easily approach (and may exceed) this level. Material and Method. We describe a healthy 21-year old nulliparous patient admitted in active labor at 39-weeks' gestational age. Results. Blood appeared asymptomatically in the left ear canal at delivery during active, closed-glottis pushing. Otoscopic examination confirmed perforation of the left tympanic membrane. Complete resolution of the eardrum rupture was noted at postpartum check-up six weeks later. Conclusion. While the precise incidence of intrapartum tympanic membrane rupture is not known, it may be unrecognized without gross blood in the ear canal or subjective hearing loss following delivery. Only one prior published report on tympanic membrane perforation during delivery currently appears in the medical literature; this is the first English language description of the event. Since a vigorous and repetitive valsalva effort is common in normal vaginal delivery, clinicians should be aware of the potential for otic complications associated with the increased intraabdominal pressure characteristic of this technique

    Lower Limb Graduated Compression Garments Modulate Autonomic Nervous System and Improve Post-Training Recovery Measured via Heart Rate Variability

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    International Journal of Exercise Science 13(7): 1794-1806, 2020. Prior studies have examined the benefits of graduated compression garments (GCG) with regards to diverse exercise regimens; however, the relationship between GCG and the autonomic nervous system (ANS) has not been fully explored. The aim of this study was to examine Heart Rate Variability (HRV) trends—a proxy for ANS modulation—in response to donning GCG during a progressive overload training regimen designed to induce overtraining. Ten college-aged male novice runners were recruited for the 8-week crossover study. After three weeks of monitored free living, participants were randomized and blinded to an intervention group that donned a lower-body GCG during a two-week exercise regimen or a control group that donned a visually identical but non-compressive sham during identical training. No significant difference in HRV was calculated by the natural logarithm of the root mean square of successive RR-interval differences (lnRMSSD) between the 3-week free-living baseline and GCG intervention periods (P = 0.3040). The mean lnRMSSD was greater during the free-living phase and GCG intervention compared to the sham placebo (P \u3c 0.001 and \u3c0.001 respectively). With regard to the daily fluctuation of lnRMSSD, no significant differences were found between free-living and intervention (P = 1.000). Conversely, the intervention period demonstrated reduced daily fluctuation of lnRMSSD relative to the Sham placebo group (P = 0.010). These novel findings posit that post training use of a commercially available graduated compression garment in novice runners may be effective in counteracting some deleterious effects from overtraining while attenuating its effects on vagally-mediated HRV

    Energy Expenditure and Muscular Recruitment Patterns of Riding a Novel Electrically Powered Skateboard

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    International Journal of Exercise Science 13(4): 1783-1793, 2020. Analysis of metabolic gas exchange and muscular output measures have enabled researchers to index activity intensity and energy expenditure for a myriad of exercises. However, there is no current research that investigates the physiological demands of riding electrically powered skateboards. The aim of this study was to measure the energetic cost and muscular trends of riding a novel electrically powered skateboard engineered to emulate snowboarding on dry-land. While riding the skateboard, eight participants (aged 21-37 years, 1 female) donned a portable breath-by-breath gas analyzer to measure energy expenditure (mean = 12.5, SD = 2 kcal/min), maximum heart rate (mean = 158, SD = 27 bpm), and metabolic equivalent (mean = 10.5, SD = 2 kcal/kg/h). By comparison, snowboarding has a metabolic equivalent (MET) of 8.0. Per the Compendium of Physical Activities guidelines, the predicted MET values for riding an electrically powered skateboard qualifies as vigorous-intensity activity. Four participants additionally wore a surface EMG embedded garment to record the percentage of maximum voluntary contraction (%MVC) of lower limb muscle groups. The inner quadriceps had the most pronounced mean peak muscle activation of 145%MVC during frontside and 164%MVC during frontside turns. EMG recordings showed 11.7%MVC higher utilization during backside turns compared to frontside turns while riding the electrically powered skateboard, which is similar to trends observed in alpine snowboarders. Therefore, electrically powered skateboards may be a promising technology for snowboarders and non-snowboarders alike to burn calories and increase physical activity year-round

    Case Report Clinical Presentation and Conservative Management of Tympanic Membrane Perforation during Intrapartum Valsalva Maneuver

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    Background. Tympanic membrane perforation may occur when ear pressures are excessive, including valsalva maneuver associated with active labor and vaginal delivery. A pressure differential across the eardrum of about 5 psi can cause rupture; the increased intraabdominal pressure spikes repeatedly manifested by "pushing" during second-stage labor easily approach (and may exceed) this level. Material and Method. We describe a healthy 21-year old nulliparous patient admitted in active labor at 39-weeks' gestational age. Results. Blood appeared asymptomatically in the left ear canal at delivery during active, closed-glottis pushing. Otoscopic examination confirmed perforation of the left tympanic membrane. Complete resolution of the eardrum rupture was noted at postpartum check-up six weeks later. Conclusion. While the precise incidence of intrapartum tympanic membrane rupture is not known, it may be unrecognized without gross blood in the ear canal or subjective hearing loss following delivery. Only one prior published report on tympanic membrane perforation during delivery currently appears in the medical literature; this is the first English language description of the event. Since a vigorous and repetitive valsalva effort is common in normal vaginal delivery, clinicians should be aware of the potential for otic complications associated with the increased intraabdominal pressure characteristic of this technique. Background Rupture of the tympanic membrane can result from any pressure or stress exerted on the ear. The vigorous and repetitive valsalva efforts of active labor can yield internal ear pressures that exceed the safe threshold for tympanic membrane integrity, causing intrapartum injury to the eardrum. Intrapartum tympanic membrane rupture appears to be encountered with low frequency, although underreporting could be a result of inadequate clinical familiarity and minimal awareness of the condition. Clinical Presentation A 21-year-old nonsmoking nullipara presented at 39-weeks' gestation in active labor. Her prenatal course was unremarkable; results from all routine prenatal laboratory tests were normal. The patient had no prior ear infections, tympanoplasty or other surgery, and her baseline evaluation identified no deficit in hearing acuity. With the exception of prenatal vitamins, she took no regular medications. Social history was negative for diving, mountainclimbing, skydiving or other activities at barometric pressure extremes. Intravenous oxytocin was not indicated for labor augmentation. Fetal status remained reassuring and the patient achieved full cervical dilation and effacement within 90 min of admission. Neither neuraxial anaesthesia nor intravenous narcotics were required for pain management. Upon confirmation of full cervical dilation, the patient began closed-glottis pushing simultaneous with uterine contractions. Following a 32-minute second stage of labor, she delivered a viable male infant over a mediolateral episiotomy. Five and ten minute Apgar scores were 9 and 9; birth weight was 3291 g. The placenta was delivered spontaneously and intact. The episiotomy was repaired routinely. Intrapartum blood loss was approximately 300 mL. Case Reports in Medicine Mother and baby did well following delivery. While the mother had no complaints in the postpartum period, she was noted to have several new small petechiae on her face and blood in her left ear about one hour after delivery. The right ear appeared grossly normal and the patient denied placing anything in the ear. However, otoscopic examination of the left external auditory canal revealed minimal dark blood and 1 cm superficial thrombus blocked a clear view of the eardrum. No active bleeding was observed and the patient remained afebrile. The patient reported no ear pain and denied any reduction in hearing sensitivity from either ear. Gentle extraction resulted in removal of the clot, revealing a 2-3 mm perforation in the inferior aspect of the left tympanic membrane. Otic lavage with bulb-syringe was not performed. Consultation with an ophthalmologist confirmed left tympanic membrane perforation. The contralateral tympanic membrane was intact. Cotton packing was placed in the ear canal and the left tympanic membrane was allowed to heal; antibiotics were not prescribed. At the postpartum follow-up exam six weeks later, the patient had no complaint and no additional ear bleeding was reported. She had no ear pain or hearing deficit, and the left eardrum appeared grossly normal. The patient was counseled to treat future ear infections promptly, to seek treatment immediately should any ear discharge be noted, and to avoid insertion of any object into the ear to clean it

    From working collections to the World Germplasm Project: agricultural modernization and genetic conservation at the Rockefeller Foundation

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    This paper charts the history of the Rockefeller Foundation’s participation in the collection and long-term preservation of genetic diversity in crop plants from the 1940s through the 1970s. In the decades following the launch of its agricultural program in Mexico in 1943, the Rockefeller Foundation figured prominently in the creation of world collections of key economic crops. Through the efforts of its administrators and staff, the foundation subsequently parlayed this experience into a leadership role in international efforts to conserve so-called plant genetic resources. Previous accounts of the Rockefeller Foundation’s interventions in international agricultural development have focused on the outcomes prioritized by foundation staff and administrators as they launched assistance programs and especially their characterization of the peoples and ‘‘problems’’ they encountered abroad. This paper highlights instead how foundation administrators and staff responded to a newly emergent international agricultural concern—the loss of crop genetic diversity. Charting the foundation’s responses to this concern, which developed only after agricultural modernization had begun and was understood to be produced by the successes of the foundation’s own agricultural assistance programs, allows for greater interrogation of how the foundation understood and projected its central position in international agricultural research activities by the 1970s.Research for this article was supported in part by a grant-in-aid from the Rockefeller Archive Center

    Targeted transcriptomics reveals signatures of large-scale independent origins and concerted regulation of effector genes in Radopholus similis.

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    The burrowing nematode, Radopholus similis, is an economically important plant-parasitic nematode that inflicts damage and yield loss to a wide range of crops. This migratory endoparasite is widely distributed in warmer regions and causes extensive destruction to the root systems of important food crops (e.g., citrus, banana). Despite the economic importance of this nematode, little is known about the repertoire of effectors owned by this species. Here we combined spatially and temporally resolved next-generation sequencing datasets of R. similis to select a list of candidates for the identification of effector genes for this species. We confirmed spatial expression of transcripts of 30 new candidate effectors within the esophageal glands of R. similis by in situ hybridization, revealing a large number of pioneer genes specific to this nematode. We identify a gland promoter motif specifically associated with the subventral glands (named Rs-SUG box), a putative hallmark of spatial and concerted regulation of these effectors. Nematode transcriptome analyses confirmed the expression of these effectors during the interaction with the host, with a large number of pioneer genes being especially abundant. Our data revealed that R. similis holds a diverse and emergent repertoire of effectors, which has been shaped by various evolutionary events, including neofunctionalization, horizontal gene transfer, and possibly by de novo gene birth. In addition, we also report the first GH62 gene so far discovered for any metazoan and putatively acquired by lateral gene transfer from a bacterial donor. Considering the economic damage caused by R. similis, this information provides valuable data to elucidate the mode of parasitism of this nematode

    Progenitor-Derivative Relationships of Hordeum Polyploids (Poaceae, Triticeae) Inferred from Sequences of TOPO6, a Nuclear Low-Copy Gene Region

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    Polyploidization is a major mechanism of speciation in plants. Within the barley genus Hordeum, approximately half of the taxa are polyploids. While for diploid species a good hypothesis of phylogenetic relationships exists, there is little information available for the polyploids (4×, 6×) of Hordeum. Relationships among all 33 diploid and polyploid Hordeum species were analyzed with the low-copy nuclear marker region TOPO6 for 341 Hordeum individuals and eight outgroup species. PCR products were either directly sequenced or cloned and on average 12 clones per individual were included in phylogenetic analyses. In most diploid Hordeum species TOPO6 is probably a single-copy locus. Most sequences found in polyploid individuals phylogenetically cluster together with sequences derived from diploid species and thus allow the identification of parental taxa of polyploids. Four groups of sequences occurring only in polyploid taxa are interpreted as footprints of extinct diploid taxa, which contributed to allopolyploid evolution. Our analysis identifies three key species involved in the evolution of the American polyploids of the genus. (i) All but one of the American tetraploids have a TOPO6 copy originating from the Central Asian diploid H. roshevitzii, the second copy clustering with different American diploid species. (ii) All hexaploid species from the New World have a copy of an extinct close relative of H. californicum and (iii) possess the TOPO6 sequence pattern of tetraploid H. jubatum, each with an additional copy derived from different American diploids. Tetraploid H. bulbosum is an autopolyploid, while the assumed autopolyploid H. brevisubulatum (4×, 6×) was identified as allopolyploid throughout most of its distribution area. The use of a proof-reading DNA polymerase in PCR reduced the proportion of chimerical sequences in polyploids in comparison to Taq polymerase
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