Curves with Canonical Models on Scrolls

Let $C$ be an integral and projective curve whose canonical model $C'$ lies on a rational normal scroll $S$ of dimension $n$. We mainly study some properties on $C$, such as gonality and the kind of singularities, in the case where $n=2$ and $C$ is non-Gorenstein, and in the case where $n=3$, the scroll $S$ is smooth, and $C'$ is a local complete intersection inside $S$. We also prove that a rational monomial curve with just one singular point lies on a surface scroll if and only if its gonality is at most $3$, and that it lies on a threefold scroll if and only if its gonality is at most $4$

Groundwater nutrient availability controls on nearshore benthic community structure in Biscayne Bay, Florida

Most studies have focused on nutrient inputs from rivers, atmosphere, and nonpoint runoff. One often overlooked source of nutrient loading is submarine groundwater discharge. For this reason, a 207 site survey and four transects were established to document spatial distribution of macrophytes, quantify potential groundwater discharge and associated nutrient concentrations, estimate water column nutrient concentrations, and relate nutrient availability to seagrass stoichiometry. A significant decline in Thalassia testudinum and an associated increase in Halodule wrightii were significantly correlated with decreased salinity and increased ammonium and total phosphorus concentrations from surface and groundwater. Total phosphorus loading from groundwater was estimated to be 2.55 metric tons y-1 in the Black Point area, almost half the phosphorus load to all of southern Biscayne Bay from the canals. These findings indicate that nutrients in groundwater are important in determining seagrass community structure and spatial distribution in the shallow waters of Biscayne Bay

KEY DRIVERS FOR ASSESSMENT CHANGE IN UNCERTAIN TIMES

In March 2020, Federation University made the decision to move all courses to be fully online due to the COVID-19 pandemic. Staff were required to rapidly adapt both their course materials and assessment tasks into an online form, including all invigilated written exams. This study aimed to investigate key drivers for assessment change for staff and in particular staff perceptions of the likely long-term impact of this rapid change based on their experience in 2020. A mixed methods approach was used to investigate staff experience and drivers of assessment change. Staff completed an online questionnaire consisting of both qualitative and quantitative items, with a focus on their experience of rapid assessment change and other influencing characteristics such as general self-efficacy, personality aspects and perceived support. Interviews were also offered for those who wished to elaborate further. While staff found the need for rapid change to be challenging, they also saw benefits that mean these changes are likely to be implemented in full or hybrid on a permanent basis. Results of the current study provide insight regarding impacts on assessment choices, support mechanisms and factors that influence assessment change

Local Food Innovation in a World of Wicked Problems: The Pitfalls and the Potential

Food-oriented markets, such as food innovation districts (FIDs), have been touted as potential methods to address complex societal issues involving the environment, poverty, and health. On this front the Grand Rapids Downtown Market (DTM) was created in 2013, envisioned as a vibrant public space for local food, entrepreneurship, community health, and jobs. An innovative, collective response to the interconnected and urgent problems of poverty, access, health, diet, and environment, the DTM can serve as a case study through which the value and necessity of a wicked problems framework become apparent. Wicked problems literature demonstrates that collaborative and iterative processes are essential to effective and inclusive transformational change of food systems, while also emphasizing that there can be no final, ideal solution. On the other hand, as an FID intentionally located in a low-income neighborhood, the DTM has been subject to criticism about top-down, expensive, and exclusionary practices aimed at gentrification. In the end, this analysis suggests that while FIDs can address local problems resulting from dominant food systems and practices, they can also function as a gentrifying force. Efforts more directly aimed at bottom-up, participatory engagement are essential to making collectively systemic, equitable changes in current food systems and practices. Emphasizing the need for bridge institutions, we argue that it is essential to value actively a wider array of knowledge cultures

The N250 Brain Potential to Personally Familiar and Newly Learned Faces and Objects

Studies employing event-related potentials have shown that when participants are monitoring for a novel target face, the presentation of their own face elicits an enhanced negative brain potential in posterior channels approximately 250 ms after stimulus onset. Here, we investigate whether the own face N250 effect generalizes to other highly familiar objects, specifically, images of the participant’s own dog and own car. In our experiments, participants were asked to monitor for a pre-experimentally unfamiliar target face (Joe), a target dog (Experiment 1: Joe’s Dog) or a target car (Experiment 2: Joe’s Car). The target face and object stimuli were presented with non-target foils that included novel face and object stimuli, the participant’s own face, their own dog (Experiment 1), and their own car (Experiment 2). The consistent findings across the two experiments were the following: (1) the N250 potential differentiated the target faces and objects from the non-target face and object foils and (2) despite being non-targets, the own face and own objects produced an N250 response that was equal in magnitude to the target faces and objects by the end of the experiment. Thus, as indicated by its response to personally familiar and recently familiarized faces and objects, the N250 component is a sensitive index of individuated representations in visual memory

Thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS): a 24-year clinical experience with 178 patients

BACKGROUND: Thrombotic thrombocytopenic purpura and the hemolytic uremic syndrome (TTP-HUS) are related and uncommon disorders with a high fatality and complication rate if untreated. Plasma exchange therapy has been shown to produce high response rates and improve survival in patients with many forms of TTP-HUS. We performed a retrospective cohort study of 178 consecutively treated patients with TTP-HUS and analyzed whether clinical or laboratory characteristics could predict for important short- and long-term outcome measures. RESULTS: Overall 30-day mortality was 16% (n = 27). 171 patients (96%) received plasma exchange as the principal treatment, with a mean of 8 exchanges and a mean cumulative infused volume of 42 ± 71 L of fresh frozen plasma. The rate of complete response was 65% or 55% depending on whether this was defined by a platelet count of 100,000/μl or 150,000/μl, respectively. The rate of relapse was 18%. The Clinical Severity Score did not predict for 30-day mortality or relapse. The time to complete response did not predict for relapse. Renal insufficiency at presentation was associated with a decreased risk of relapse, with each unit increase in serum creatinine associated with a 40% decreased odds of relapse. 72% of our cohort had an idiopathic TTP-sporadic HUS, while 17% had an underlying cancer, received a solid organ transplant or were treated with a mitomycin-based therapy. The estimated overall 5-year survival was 55% and was significantly better in those without serious underlying conditions. CONCLUSION: Plasma exchange therapy produced both high response and survival rates in this large cohort of patients with TTP-HUS. The Clinical Severity Score did not predict for 30-day mortality or relapse, contrary to our previous findings. Interestingly, the presence of renal insufficiency was associated with a decreased risk of relapse. The most important predictor of mortality was the presence or absence of a serious underlying disorder

Ultrafast Excited-State Decay Mechanisms of 6-Thioguanine Followed by Sub-20 fs UV Transient Absorption Spectroscopy

: Understanding the primary steps following UV photoexcitation in sulphur-substituted DNA bases (thiobases) is fundamental for developing new phototherapeutic drugs. However, the investigation of the excited-state dynamics in sub-100 fs time scales has been elusive until now due to technical challenges. Here, we track the ultrafast decay mechanisms that lead to the electron trapping in the triplet manifold for 6-thioguanine in an aqueous solution, using broadband transient absorption spectroscopy with a sub-20 fs temporal resolution. We obtain experimental evidence of the fast internal conversion from the S2(ππ*) to the S1(nπ*) states, which takes place in about 80 fs and demonstrates that the S1(nπ*) state acts as a doorway to the triplet population in 522 fs. Our results are supported by MS-CASPT2 calculations, predicting a planar S2(ππ*) pseudo-minimum in agreement with the stimulated emission signal observed in the experiment

Mechanisms of Alcohol Addiction: Bridging Human and Animal Studies

Aim: The purpose of this brief narrative review is to address the complexities and benefits of extending animal alcohol addiction research to the human domain, emphasizing Allostasis and Incentive Sensitization, two models that inform many pre-clinical and clinical studies. Methods: The work reviewed includes a range of approaches, including: a) animal and human studies that target the biology of craving and compulsive consumption; b) human investigations that utilize alcohol self-administration and alcohol challenge paradigms, in some cases across 10 years; c) questionnaires that document changes in the positive and negative reinforcing effects of alcohol with increasing severity of addiction; and d) genomic structural equation modeling based on data from animal and human studies. Results: Several general themes emerge from specific study findings. First, positive reinforcement is characteristic of early stage addiction and sometimes diminishes with increasing severity, consistent with both Allostasis and Incentive Sensitization. Second, evidence is less consistent for the predominance of negative reinforcement in later stages of addiction, a key tenant of Allostasis. Finally, there are important individual differences in motivation to drink at a given point in time as well as person-specific change patterns across time. Conclusions: Key constructs of addiction, like stage and reinforcement, are by necessity operationalized differently in animal and human studies. Similarly, testing the validity of addiction models requires different strategies by the two research domains. Although such differences are challenging, they are not insurmountable, and there is much to be gained in understanding and treating addiction by combining pre-clinical and clinical approaches.Fil: Kramer, John. University of Iowa; Estados UnidosFil: Dick, Danielle M.. University of Virginia; Estados UnidosFil: King, Andrea. University of Chicago; Estados UnidosFil: Ray, Lara A.. University of California at Los Angeles; Estados UnidosFil: Sher, Kenneth J.. University of Missouri; Estados UnidosFil: Vena, Ashley. University of Chicago; Estados UnidosFil: Vendruscolo, Leandro F.. National Institutes of Health; Estados UnidosFil: Acion, Laura. University of Iowa; Estados Unidos. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Calculo. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Calculo; Argentin

Espécies de Lactobacillus e seu papel na vaginose bacteriana

A vaginose bacteriana representa o distúrbio ginecológico mais prevalente em mulheres com idade reprodutiva e tem como etiologia principal a alteração da microbiota vaginal normal, composta predominantemente por lactobacilos, que inibem o crescimento e a adesão de patógenos fornecendo defesa local. O gênero Lactobacillus contém mais de 80 espécies, em que os predominantes no canal vaginal da mulher em idade reprodutiva são: L. crispatus (30,1%), L. jensenii (26,5%), L. gasseri (22,9%) e L. vaginalis (8,4%), destes o L. crispatus demonstrou ser o maior produtor de acido lático e o melhor protetor contra infecções. Devido as suas características benéficas, o L. crispatus poderia ser utilizado como biomarcador de saúde vaginal e como probiótico. Os lactobacilos vaginais usados como probióticos na recolonização e na manutenção da microbiota vaginal, combinados com antibióticos ou não, podem ser eficientes no tratamento e na prevenção de infecções vaginais. Entretanto é preciso mais estudos para confirmar os benefícios do uso de probióticos no tratamento da vaginose