"On the Taketa bound for normally monomial p-groups of maximal class"

Geoffrey T. Tims is a 2003 graduate of the Department of Mathematics and Computer Science, Drake University.A longstanding problem in the representation theory of finite solvable groups, sometimes called the Taketa problem, is to find strong bounds for the derived length dl(G) in terms of the number |cd(G)| of irreducible character degrees of the group G. For p-groups an old result of Taketa implies that dl(G)|cd(G)|, and while it is conjectured that the true bound is much smaller (in fact, logarithmic) for large dl(G), it turns out to be extremely difficult to improve on Taketa's bound at all. Here, therefore, we suggest to first study the problem for a restricted class of p-groups, namely normally monomial p-groups of maximal class. We exhibit some structural features of these groups and show that if G is such a group, then .Supported by NSF REU grant #0097759

The effect of multiple sclerosis on carotid baroreflex control of heart rate and blood pressure

Multiple sclerosis (MS) is marked by conduction abnormalities within the central nervous system that can lead to impaired blood pressure regulation. However, the impact of this disease on dynamic neural control—responsiveness and timing (i.e., latency)—of blood pressure has not been examined. Utilizing a variable neck chamber system, we tested the hypothesis that patients with MS (MS: n=4) exhibit an altered response following baroreflex perturbation compared to sex and age matched healthy controls (CON: n=4). At rest, 5-sec pulses of neck suction (NS; -60 Torr) and neck pressure (NP; +40 Torr) were applied to simulate carotid hypertension and hypotension, respectively. Mean arterial pressure (MAP; Finometer) and heart rate (HR) were continuously measured in response to the perturbations. Carotid baroreflex (CBR) latencies (i.e., time-to-peak responses) were examined using carotid-cardiac (peak HR responses), carotid-vasomotor (peak MAP responses), and change in MAP at the peak HR response of the corresponding stimuli (MAP@HRpeak), all of which were not significant for both NP and NS. Following NS, responses in MAP (MS: -12±5, CON: -10±3 mmHg; p=0.43) and HR (MS: -9±3, CON: -8±4 BPM; p=0.58) were similar between groups. Following administration of NP, HR responses (MS: 4±2, CON: 5±4 BPM; p=0.47) were no different. However, the differences found in MAP were significant (MS: 5±2, CON: 8±2 mmHg; p=0.05), providing some evidence that baroreceptor responsiveness may be compromised when faced with a hypotensive challenge

The Effect of Type II Diabetes Mellitus on Oxygen Uptake Kinetics during Heavy Exercise

The kinetics of oxygen uptake (Vo2) during the rest to exercise transition are thought to be modulated by intracellular metabolic processes. Diabetes has been shown to slow Vo2 kinetics, likely due to the impact of diabetes upon microvascular oxygen exchange (Padilla et al, 2007). However, to date, recovery from exercise has yet to be studied in these patients. Thus, the purpose of this study was to test the hypothesis that the existence of diabetes would hamper Vo2 kinetics during transitions to and from heavy leg cycling (H: Supra-LT). Nine subjects (4 control, 5 diabetic) completed three separate H exercise bouts. Vo2 was measured continuously at the mouth during exercise and recovery for each bout. During the on-transient, the total amplitude was decreased (Atot: Control 2.16±0.29 vs Diabetic 1.33±0.42 L/min, p=0.01). In an attempt to correct for differences in Atot, the rate of change in Vo2 (A1/T1 ) was calculated. This variable was significant reduced in diabetics during both the on-(A1/T1: Control 0.059±0.03 vs Diabetic 0.016±0.01, p=0.02), and off-transients (Control -0.10±0.10 vs Diabetic 0.035±0.012, p=0.09). In addition, the time constant during the on-transition was greatly slowed in diabetes (Tau: Control 24.07±8.39 vs Diabetic 76.76±37.94 sec, p=0.03). These findings suggest strongly that diabetes and it’s sequelae lead to impairments in oxidative metabolism during both exercise and recovery, which would serve to cause a faster rate of fatigue and a longer temporal course of recovery

Increased incidence and risk of septicemia and urinary tract infection after Clostridioides difficile infection

BACKGROUND: Although increased occurrence of septicemia in persons with METHODS: The first episode of CDI was identified using 2011-2017 MarketScan and CMS Medicare data and CDI cases categorized by standard surveillance definitions. Uninfected persons were frequency matched 4:1 to cases by the CDI case surveillance definition. Multivariable Cox proportional hazards models were used to identify risk factors for septicemia and UTI within 90 days of CDI onset, accounting for the competing risk of death in the Medicare population. RESULTS: The incidence of septicemia was highest after hospital-onset CDI in the Medicare, younger commercial, and younger Medicaid populations (25.5%, 15.7%, and 19.5%, respectively) and lowest in those with community-associated CDI (3.8%, 4.3%, and 8.3%, respectively). In contrast, the incidence of UTI was highest in those with other healthcare facility onset CDI in all 3 populations (32.1%, 24.2%, and 18.1%, respectively). Hospital-onset CDI was associated with highest risk of septicemia compared with uninfected controls in all 3 populations. In the younger populations, risk of septicemia was more uniform across the CDI surveillance definitions. The risk of UTI was significantly higher in all CDI surveillance categories compared to uninfected controls, and among CDI cases it was lowest in those with community-associated CDI. CONCLUSIONS: The incidence of septicemia is high after CDI, particularly after hospital-onset infection. Additional preventive measures are needed to reduce infectious complications of CDI

Carotid Baroreflex Responses to Simulated Hypotension are Blunted During Passive Whole-body Heat Stress in Young Women

Previous studies have proposed that carotid baroreflex (CBR) function is potentially compromised during heat stress, thus possibly disrupting the ability to maintain arterial blood pressure in the heat (e.g., decreased orthostatic tolerance during hyperthermia). Recently, we demonstrated that CBR function is preserved, if not enhanced, during a passive whole-body heat stress (WBH) in young healthy men. What remains unknown is how CBR function is impacted by hyperthermia in women. PURPOSE: Therefore, the purpose of this study was to test the hypothesis that CBR-mediated responses are preserved during a passive WBH in young women. METHODS: Changes in mean arterial pressure (MAP) and HR were assessed in 7 healthy women (age: 21±1 yrs, height: 171±5 cm, weight: 66±5 kg, BMI: 23±2 kg/m2) using 5-s trials of neck pressure (NP, carotid hypotension) and neck suction (NS, carotid hypertension) ranging from +40 to -80 Torr during normothermia (NT) and WBH (increased core temp ~1.0 °C) conditions. To assess the CBR control of MAP and HR, a separate two-way repeated measures ANOVA was utilized for 1) hypertensive stimuli (i.e., NS: -20, -40, -60 & -80 Torr) and 2) hypotensive-stimuli (i.e., NP: +20 & +40 Torr). Additionally, the time-to-peak responses for HR and MAP, separately, in response +40 Torr & -80 Torr trials were examined between thermal conditions using paired t-tests. RESULTS: During WBH, the CBR-mediated increases in MAP and HR in response to NP were blunted (main effect of thermal condition p=0.02 and p=0.02, respectively). While the CBR-mediated decreases in MAP in response to NS were not different between thermal conditions (main effect of thermal condition p=0.34), decreases in HR were markedly greater during WBH (main effect of thermal condition p\u3c0.001). Additionally, the time-to-peak responses for MAP and HR were not altered between thermal conditions for either NP or NS trials (p \u3e 0.05 for all comparisons). CONCLUSION: Taken together, these data suggest the CBR control of MAP and HR during simulated hypotension is blunted in females during passive WBH, while the control of MAP and HR seems to be preserved, if not enhanced, during simulated hypertension. Contrary to our findings in young men, these results suggest there are sex differences in CBR function during WBH. This diminished ability to increase MAP and HR in response to a hypotensive stimulus during hyperthermia may be a key component in reduced orthostatic tolerance in females during WBH

Evolution Of A Higher Intracellular Oxidizing Environment In Caenorhabditis Elegans Under Relaxed Selection

We explored the relationship between relaxed selection, oxidative stress, and spontaneous mutation in a set of mutation-accumulation (MA) lines of the nematode Caenorhabditis elegans and in their common ancestor. We measured steady-state levels of free radicals and oxidatively damaged guanosine nucleosides in the somatic tissues of five MA lines for which nuclear genome base substitution and GC-TA transversion frequencies are known. The two markers of oxidative stress are highly correlated and are elevated in the MA lines relative to the ancestor; point estimates of the per-generation rate of mutational decay (DM) of these measures of oxidative stress are similar to those reported for fitness-related traits. Conversely, there is no significant relationship between either marker of oxidative stress and the per-generation frequencies of base substitution or GC-TA transversion. Although these results provide no direct evidence for a causative relationship between oxidative damage and base substitution mutations, to the extent that oxidative damage may be weakly mutagenic in the germline, the case for condition-dependent mutation is advanced

Extraction of Generalized Parton Distribution Observables from Deeply Virtual Electron Proton Scattering Experiments

We provide the general expression of the cross section for exclusive deeply virtual photon electroproduction from a spin 1/2 target using current parameterizations of the off-forward correlation function in a nucleon for different beam and target polarization configurations up to twist three accuracy. All contributions to the cross section including deeply virtual Compton scattering, the Bethe-Heitler process, and their interference, are described within a helicity amplitude based framework which is also relativistically covariant and readily applicable to both the laboratory frame and in a collider kinematic setting. Our formalism renders a clear physical interpretation of the various components of the cross section by making a connection with the known characteristic structure of the electron scattering coincidence reactions. In particular, we focus on the total angular momentum, $J_z$, and on the orbital angular momentum, $L_z$. On one side, we uncover an avenue to a precise extraction of $J_z$, given by the combination of generalized parton distributions, $H+E$, through a generalization of the Rosenbluth separation method used in elastic electron proton scattering. On the other, we single out for the first time, the twist three angular modulations of the cross section that are sensitive to $L_z$. The proposed generalized Rosenbluth technique adds an important constraint for mapping the 3D structure of the nucleon.Comment: 62 pages, 7 figures, 3 table

Phase I of the Detecting and Evaluating Childhood Anxiety and Depression Effectively in Subspecialties (DECADES) Study: Development of an Integrated Mental Health Care Model for Pediatric Gastroenterology

Background: Children with gastrointestinal symptoms have a very high rate of anxiety and depression. Rapid identification of comorbid anxiety and depression is essential for effective treatment of a wide variety of functional gastrointestinal disorders. Objective: The objective of our study was to determine patient and parent attitudes toward depression, anxiety, and mental health screening during gastroenterology (GI) visits and to determine patient and parent preferences for communication of results and referral to mental health providers after a positive screen. Methods: We augmented standard qualitative group session methods with patient-centered design methods to assess patient and parent preferences. We used a variety of specific design methods in these sessions, including card sorting, projective methods, experience mapping, and constructive methods. Results: Overall, 11 families (11 patients and 14 parents) participated in 2 group sessions. Overall, patients and their parents found integrated mental health care to be acceptable in the subspecialty setting. Patients’ primary concerns were for the privacy and confidentiality of their screening results. Patients and their parents emphasized the importance of mental health services not interfering with the GI visit and collaboration between the GI physician, psychologist, and primary care provider. Conclusions: Patients and their families are open to integrated mental health care in the pediatric subspecialty clinic. The next phase of the DECADES study will translate patient and parent preferences into an integrated mental health care system and test its efficacy in the pediatric GI office. [J Participat Med 2018;10(3):e10655

Evolution of a Higher Intracellular Oxidizing Environment in Caenorhabditis elegans under Relaxed Selection

We explored the relationship between relaxed selection, oxidative stress, and spontaneous mutation in a set of mutation-accumulation (MA) lines of the nematode Caenorhabditis elegans and in their common ancestor. We measured steady-state levels of free radicals and oxidatively damaged guanosine nucleosides in the somatic tissues of five MA lines for which nuclear genome base substitution and GC-TA transversion frequencies are known. The two markers of oxidative stress are highly correlated and are elevated in the MA lines relative to the ancestor; point estimates of the per-generation rate of mutational decay (DM) of these measures of oxidative stress are similar to those reported for fitness-related traits. Conversely, there is no significant relationship between either marker of oxidative stress and the per-generation frequencies of base substitution or GC-TA transversion. Although these results provide no direct evidence for a causative relationship between oxidative damage and base substitution mutations, to the extent that oxidative damage may be weakly mutagenic in the germline, the case for condition-dependent mutation is advanced