Second fundamental form of the Prym map in the ramified case

In this paper we study the second fundamental form of the Prym map $P_{g,r}: R_{g,r} \rightarrow {\mathcal A}^{\delta}_{g-1+r}$ in the ramified case $r>0$. We give an expression of it in terms of the second fundamental form of the Torelli map of the covering curves. We use this expression to give an upper bound for the dimension of a germ of a totally geodesic submanifold, and hence of a Shimura subvariety of ${\mathcal A}^{\delta}_{g-1+r}$, contained in the Prym locus.Comment: To appear in Galois Covers, Grothendieck-Teichmueller Theory and Dessins d'Enfants - Interactions between Geometry, Topology, Number Theory and Algebra. Springer Proceedings in Mathematics & Statistics. arXiv admin note: text overlap with arXiv:1711.0342

DEMOGRAPHICS AND THE ECOLOGICAL ROLE OF THE CHANNEL CATFISH (ICTALURUS PUNCTATUS) IN COMMERCIALLY EXPLOITED AND UNEXPLOITED REACHES OF THE WABASH RIVER WITH IMPLICATIONS FOR THE FLATHEAD CATFISH (PYLODICTIS OLIVARIS)

Catfish are a major component of the Wabash River fish assemblage and are commercially fished below river kilometer (Rkm) 500. From Rkm 322 through 499 the commercial fishery is subjected only to Indiana fishing regulations. In this reach of river, there is a 254-mm minimum total length limit on both sport and commercially harvested catfish. Below RM 322, the Wabash River forms the state boundary of Indiana and Illinois. In this region of river there are two different length limits on commercially harvested catfish with Indiana having a 254-mm length limit and Illinois having a 381-mm length limit. There is no length limit on sport harvest of catfish by Illinois anglers; however, there is a 254-mm length limit on the Indiana sport fishers. The primary objective of this study was to assess the general population dynamics of the channel catfish (Ictalurus punctatus) under various sport and commercial fishing regulations and to determine the sources of energy for this species. To accomplish this, I sampled both fished (IN, IN & IL) and unfished (NON) treatment reaches of the Wabash River during fall 2001 through 2004 using three-phase alternating current (AC) electrofishing and cheese baited, 25-mm and 32-mm bar-mesh hoop nets. Of the 2,807 catfish collected, 91% were channel, 8% were flathead (Pylodictis olivaris) and 1% were blue catfish (I.furcatus). Length frequency distributions and mean age of fish differed across the three different gear types (P \u3c 0.02), with electrofishing sampling larger, older channel catfish. Densities estimated from catch per unit effort (CPUE) did not differ among treatment reaches (NON, IN, IN & IL) using hoop nets (25-mm: P \u3c 0.1, 32-mm: P = 0.4); however, electrofishing CPUE was greater in the unfished reach compared to the two commercially exploited reaches (P \u3c 0.001). Additionally, length frequency distributions and stock indices differed among treatment reaches (P = 0.017). As suggested by the high relative stock density of preferred length fish (RSD-P) values, more large catfish resided in the unfished reach than the fished reaches. Age structure also varied among reaches. More old fish were in the commercially unexploited treatment reach, leading to greater mean age (P \u3c 0.005). Ages derived from the articulating process of the pectoral spine agreed well with those determined from the sagittal otolith. Mortality estimated from the slope of the regression of age on Log10 frequency (catch curve) was greater for both gear types in the commercially exploited reaches than in the non exploited reach. Mean length at age 5 and condition of channel catfish was greater in the commercially exploited reaches than the unexploited reach. There was a positive relationship between channel catfish electrofishing CPUE and habitat quality as measured by the qualitative habitat assessment index (QHEI). Yield-per-recruit modeling of the commercially exploited river reaches predicted that at the current level of harvest the channel catfish fishery is sustainable; however, if both states adopted a 254-mm length limit and fishing mortality increased both growth and recruitment overfishing would likely occur even at fairly low levels of harvest (30% fishing mortality). Yield-per-recruit modeling of the flathead catfish population suggested this population was not sustainable at any of the length limits modeled. Based on stable isotope analysis of δ13C and δ15N, channel catfish did not differ in their trophic status among the treatment reaches, and the structures of the food webs among reaches were similar. These results provide additional support to the hypothesis that growth and condition are functions of density. The results of this study suggest that a harvest reserve in a large river acts similarly to marine reserves, in that density increases on the reserve lead to decreased growth and condition of individuals on the reserve

Reproductive Demographics and Early Life History of the Shovelnose Sturgeon (SCAPHIRHYNCHUS PLATORYNCHUS)

Due to the collapse of the historic caviar fisheries in the Volga River and Caspian Sea, the demand on domestically produced caviar has increased. To supply the increased demand, the harvest of the shovelnose sturgeon Scaphirhynchus latorynchus has increased. Because caviar fisheries preferentially harvest females, information regardingthe sexual demographics of these populations is essential for effective fisheries management. To date, knowledge regarding the sex ratios and reproductive development of the shovelnose sturgeon population in the Middle Mississippi River is lacking. In Chapter 1, I describe this problem in detail and in subsequent chapters I explain how I addressed this problem using a combination of field and laboratory techniques. The shovelnose sturgeon and other acipenserids have no known sexually dimorphic traits, making field identification of sex difficult. Thus, in Chapter 2, I developed a non-surgical method for the determination of sex of shovelnose sturgeon. Ultrasound imaging was used to determine the sex of shovelnose sturgeon (n=51). Overall, ultrasound imaging provided an effective method for determining sex, with 86% correct identification of all individuals examined. Ultrasound was ineffective at determining the sex of post spawn females, with 60% being incorrectly identified as males. This method would allow managers to quickly identify sex in the field so that the sex ratio of the shovelnose sturgeon populations could be tracked and population dynamics can be modeled. Understanding of the sequence of gonadal development allows for the determination of spawning stock size in a given year. This information is currently lacking for the shovelnose sturgeon. To address this, I developed a guide for shovelnose sturgeon reproductive development in Chapter 3. Shovelnose sturgeon were sampled seasonally from the Middle Mississippi River to account for all stages of reproductivedevelopment. I found that stages of gonadal development of the shovelnose sturgeon were both grossly and histologically similar to those of other sturgeon species. This sample allowed me to estimate the sex ratio in the population using an unbiased approach. The shovelnose sturgeon population in the MMR did not differ from 1: 1. The shovelnose sturgeon has been extirpated from several portions of its historic range. Conservation aquaculture can be used to reestablish shovelnose sturgeon populations to these regions. This requires detailed information about early life history which is currently unavailable. In Chapter 4, I described the stages of development of embryonic and larval shovelnose sturgeon to resolve this issue, giving culturists the ability to track the development of their spawn using proper development as an indicator of success. Additionally, otoliths provide little use in determining hatch date in the acipenserids. Using this information, managers will be able to determine hatch date using stage of development and river temperature

Automatic generation of human machine interface screens from component-based reconfigurable virtual manufacturing cell

Increasing complexity and decreasing time-tomarket require changes in the traditional way of building automation systems. The paper describes a novel approach to automatically generate the Human Machine Interface (HMI) screens for component-based manufacturing cells based on their corresponding virtual models. Manufacturing cells are first prototyped and commissioned within a virtual engineering environment to validate and optimise the control behaviour. A framework for reusing the embedded control information in the virtual models to automatically generate the HMI screens is proposed. Finally, for proof of concept, the proposed solution is implemented and tested on a test rig

Regulating Risk in a Managed Care Environment: Theory vs. Practice, The Minnesota Experience

The purpose of this Article is to illustrate the challenges state regulators face when attempting to translate theory into practice in the context of health care risk regulation. Section I reviews the evolution of the risk-bearing market in health care, recognizing that while risk is an inherent part of everyday life, it takes on a delicate meaning when used in the context of health care. Cost and demographic data will be discussed to provide a compelling rationale for the ongoing forceful movement toward cost containment strategies embodied in managed care strategies, as well as the need to develop the next generation of risk-bearing entities. Sections II and III provide an overview of state health care regulation and an examination of Minnesota\u27s regulatory experience. Sections IV through VII detail the emergence and ongoing development of direct contracting strategies. Throughout this Article, strategies will be reviewed from both a theoretical and practical perspective. These experiences can teach valuable lessons and underscore the challenges inherent in translating theory into practice, and the obvious, yet unwilling tradeoffs that are necessary to truly reform the health care regulatory infrastructure. The Article will conclude with a set of guiding principles that should be considered by state regulators in the development and oversight of new and emerging risk-bearing entities

Effects of Dams on the genetic structure of fish assemblages in the Vermilion River

U.S. Department of the InteriorU.S. Geological SurveyOpe

Use of Ultrasound Imaging to Determine Sex of Shovelnose Sturgeon

During November 2002, 51 shovelnose sturgeon Scaphirhynchus platorynchus were sexed by ultrasound imaging using a portable ultrasonograph. We identified males with 96% accuracy (N = 25) and females with 80% accuracy (N = 25); one hermaphroditic individual was misidentified as a male. Overall, ultrasound imaging was 86% accurate. Sex in postspawned females was difficult to determine, 60% being misidentified as males (N = 5). Ultrasonography is an effective noninvasive method for sex determination that can be applied to other species of Acipenseriformes. Modern portable equipment expands its utility to field studies

Declining Recruitment and Growth of Shovelnose Sturgeon in the Middle Mississippi River: Implications for Conservation

To determine how populations of shovelnose sturgeon Scaphirhynchus platorynchus are changing and may respond to poor environmental conditions, current commercial harvest of black-egg (sexually mature) females, and incidental mortality of males, we require annual information about sex-specific age structure as it relates to the recruitment of new cohorts. We sampled shovelnose sturgeon by use of gill nets (5-cm bar mesh) monthly during 2002-2006 in the Middle Mississippi River between Cairo, Illinois, and St. Louis, Missouri. We compared patterns of size and age structure over time and projected age structure and population size into the future. Sex ratio in 2005-2006 was 1.14:1.00 (416 males and 363 females; P = 0.06), deviating from the 1:1 ratio that occurred in 2002-2003. Annual mortality increased from 37% in 2002-2003 to 44% by 2005-2006. Female shovelnose sturgeon were larger than males. Across years, the population shifted toward longer, older fish, and growth in length declined. Recruitment declined through time (29% per year). If these trends continue and if immigration from nonharvested populations is limited, population density may decline by an order of magnitude within one decade. Under current conditions, resilience to harvest and environmental perturbations is probably limited