Regulation of the juvenile hormone titre in the Colorado potato beetle

Three main topics were investigated in regulation of the titre of juvenile hormone in haemolymph of the Colorado potato beetle ( Leptinotarsa decemlineata Say): enzymic breakdown of the hormone; binding and protection of the hormone by carrier proteins; the synthetic capacity of the corpora allata.Juvenile hormone was broken down by two major pathways: ester hydrolysis by esterases and hydration of the epoxide group by epoxide hydratases in tissue. In haemolymph of the beetle, juvenile hormone is solely broken down by juvenile hormone esterases. An in vitro method was developed to measure the catalytic activity of juvenile hormone esterase from haemolymph. High activities were observed in fourth-instar larvae and in beetles just before diapause. Lower activities were found in third- instar larvae and in beetles reared with long days, at diapause and after diapause. The juvenile hormone esterase was insensitive to diisopropylfluorophosphate (DFP), an inhibitor used to distinguish between carboxylesterases and esterases specific to juvenile hormone. Electrophoresis of the esterase from haemolymph showed one or more esterases specific to juvenile hormone.The short half-life of juvenile hormone measured in vivo and in vitro in the haemolymph and inhibition studies with Triton X-100 suggests that juvenile hormone esterases in haemolymph govern breakdown. Activities of juvenile hormone esterase correlate well with the juvenile hormone titre.The sharp changes in juvenile hormone esterase suggest that esterase activity is regulated. The mechanism was studied by supplying juvenile hormone and by microsurgery. Treatment of diapausing beetles with juvenile hormone itself or analogues caused an increase in activity of juvenile hormone esterase within 24 h. Ligation or removal of corpora allata suggested that this induction was an indirect effect of juvenile hormone. Transfer from short day to long day and treatment with hormone of beetles reared with short days prevented high activity of juvenile hormone esterase. Removal of corpora allata at emergence from beetles reared with short days resulted in the same. In beetles reared with short days the titre of hormone during the first days after adult emergence probably induces the rise in esterase. Esterase activity is thus most likely controlled indirectly by the hormone, via a centre in the brains (hormostate). The level of esterase activity is probably dependent on the sensitivity of this hormostate and on the titre of the juvenile hormone.In several insects juvenile hormone is transported bound to carrier proteins. In haemolymph of larval and adult Colorado potato beetles lipoproteins of high molecular weight (>100,00 daltons) were found, capable of binding juvenile hormone, its analogues, and palmitic acid. The lipoproteins were partially separated by gel permeation chromatography and electrophoresis on polyacrylamide gel. The binding characteristics of the lipoproteins indicate low affinity (K d ≈10 -5 M), low specificity and high binding capacity. The juvenile hormone complexed to lipoproteins was protected against esterases from haemolymph to some extent. Thus these carrier lipoproteins probably play little role in the regulation of the titre of juvenile hormone.In the last part of our investigations the activity of the corpora allata was measured in vitro. High activities were observed in beetles reared with long days and in beetles after emergence. In beetles reared with short days, amounts of hormone produced were intermediate until Day 6 after emergence, thereafter declining to a low value. During diapause, production remained low. The production by corpus allatum and the activity of juvenile hormone esterase were in good agreement with the titre of juvenile hormone. The corpora allata are probably the primary regulator of the hormone titre in the Colorado potato beetle.<p/

How the Justice System Responds to Juvenile Victims: A Comprehensive Model.

The justice system handles thousands of cases involving juvenile victims each year. These victims are served by a complex set of agencies and institutions, including police, prosecutors, courts, and child protection agencies. Despite the many cases involving juvenile victims and the structure in place for responding to them, the juvenile victim justice system model presented in this Bulletin is a new concept. Although the juvenile victim justice system has a distinct structure and sequence, its operation is not very well understood. Unlike the more familiar juvenile offender justice system, the juvenile victim justice system has not been conceptualized as a whole or implemented by a common set of statutes. This Bulletin identifies the major elements of the juvenile victim justice system by delineating how cases move through the system. It reviews each step in the case flow process for the child protection and criminal justice systems and describes the interaction of the agencies an individuals involved. Recognizing how the juvenile victim justice system works can inform policy decisions and improve outcomes for juvenile victims. Acknowledging the existence of the system has important implications for system integration, information sharing, and data collection—all of which play a key role in ensuring the safety and well-being of juvenile victims

Opportunities for Juvenile Justice Reform

Examines recent trends that have influenced the juvenile justice population, and outlines goals and strategies for reforming the juvenile justice system. Includes opportunities for linking juvenile justice with those who work on youth employment

Addressing the Intersections of Juvenile Justice Involvement and Youth Homelessness: Principles for Change

A young person's involvement with the justice system can increase their likelihood of later experiencing homelessness for many reasons, including the fact that educational disruptions and juvenile delinquency records can make it harder to obtain employment. Youth experiencing homelessness may also be swept into the juvenile justice system through laws that prohibit simply being in public spaces, such as juvenile curfews, or anti-sitting or sleeping ordinances. Both juvenile justice involvement and youth homelessness have long-term negative consequences. The Principles in Part I of this document provide a roadmap for communities to help young people avoid experiencing juvenile justice system involvement and/or youth homelessness

The Juvenile Offender - Where can we send him?

There is an increased problem in American society regarding juvenile delinquents. Persons less than 16 years of age cannot be adjudicated criminals and nearly 80% of persons convicted of serious crimes a adults were previous convicted of a lesser offense. However, these criminals were only previously considered juvenile delinquents and not adjudicated criminals. Rehabilitation has been the main focus when dealing with juvenile delinquency and juvenile courts have operated under the theory of \u27best interests of the child\u27 and \u27parens patriae\u27. Unfortunately, family court hearings used to determine juvenile delinquency now contain the stigma of criminal proceedings rendering the theory of juvenile courts nearly dead. The problem is caused by these courts\u27 inability to carry out their purposes and many new solutions are being proposed to fight this issue. Community based rehabilitation centers, quasi-judicial panels, expanding categories of juvenile delinquency, and creating more appropriate placement facilities are all proposed plans. While there are budgetary concerns, it is essential to proceed to try and solve the problem while keeping the best interests of the child at heart

Distribution and Abundance of Juvenile Salmonids off Oregon and Washington, 1981-1985

This report is a summary of the results of 883 purse seine sets made for juvenile salmonids during 15 cruises off the coasts of Oregon and Washington during the springs and summers of 1981-1985. Juvenile coho salmon (Oncorhynchus kisutch) occurred most frequently, followed by chinook salmon (0. tshawytscha). The juveniles of these two species co-occurred more frequently than expected. Juvenile chum, pink and sockeye salmon (0. keta, O. gorbuscha, and O. nerka), steelhead (0. mykiss) and cutthroat trout (0. clarki clarki) were caught much less frequently and in lower numbers than coho or chinook salmon. We found no evidence of large schools ofjuvenile salmonids. A northerly movement of juvenile coho salmon wa~ suggested by decreased catches off Oregon and increased catches off Washington between early and late summer. Highest catch per set of juvenile coho salmon was usually found inshore of 37.2 km. Juvenile chinook salmon were usually found within 27.9 km of the coast. Juvenile salmonids were found over a broad range of surface salinities and temperatures. High catches of juvenile coho salmon occurred in both the low salinity waters of the Columbia River plume and in adjacent higher salinity waters. Preferences for specific salinities or temperatures were not obvious for any species, although catch rates of juvenile coho salmon were highest in years when chlorophyll content was also high. Based on expansions of fish with coded wire tags, we estimated that hatchery coho salmon smolts comprised 74%, on average, of the juvenile coho salmon catches. The remaining 26% were presumably wild fish or hatchery fish released as fingerlings. Hatchery coho salmon were caught roughly in proportion to the numbers released. However, hatchery fish from the Columbia River and private coastal facilities were caught at slightly higher rates while those from coastal Washington and public coastal Oregon hatcheries were caught at slightly lower rates than expected from the numbers released. No juvenile coho salmon with coded wire tags were caught that had originated from either California or Puget Sound hatcheries. (PDF file contains 88 pages.

Results of abundance surveys of juvenile Atlantic and gulf Menhaden, Brevoortia tyrannus and B. patronus

The estuarine populations of juvenile Atlantic and gulf menhaden (Brevoortia tyrannus and B. patronus) were sampled during two-boat, surface-trawl, abundance surveys extensively conducted in the 1970s. Juvenile Atlantic menhaden were sampled in 39 estuarine streams along the U.S. Atlantic coast from northern Florida into Massachusetts. Juvenile gulf menhaden were sampled in 29 estuarine streams along the Gulf of Mexico from southeast Texas into western Florida. A stratified, two-stage, cluster sampling design was used. Annual estimates of relative juvenile abundance for each species of menhaden were obtained from catch-effort data from the surveys. There were no significant correlations, for either species, between the relative juvenile abundance estimates and fishery-dependent estimates of year-class strength. From 1972 to 1975, the relative abundance of juvenile Atlantic menhaden in north Atlantic estuaries decreased to near zero. (PDF file contains 22 pages.

A physiological investigation of the adaptive significance of juvenility in Pennantia corymbosa Forst : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Botany at Massey University

The responses of the juvenile and adult growth forms of Pennantia corymbosa Forst. to a range of light intensities, leaf temperatures, shoot water potentials and wind velocities were investigated. Results tend to indicate that the small-leafed divaricating juvenile is better adapted to open habitats than the adult. Responses to light intensity were similar for both growth forms. Measurements of photosynthetic rates at various light intensities after pretreatment at low and high irradiances revealed little difference in response between juvenile and adult, with both showing a similar increase in photosynthetic rates and light saturation points after the pretreatment light intensity was increased. Granal stacking in chloroplasts from juvenile and adult leaf palisade was reduced after growth at the higher pretreatment light intensity to the same extent in juveniles and adults. Solarization, despite the presence of a hypodermis, was greater in the adult, while the activity of Ribulose -1,5- diphosphate carboxylase was greater in the juvenile. The indication that the juvenile is better adapted to open habitats is also supported by the results of experiments into the response of photosynthetic rates to a range of temperatures. The data revealed a higher mean temperature optimum for the juvenile than for the adult leaves (21°C c.f. 18°C). The hypothesis that the juvenile might be better adapted to edaphic water stress was tested by withholding water for 14 days and measuring the rates of photosynthesis and transpiration as shoot water potential decreased. Rates of photosynthesis and transpiration declined in both juvenile and adult leaves as shoot water potential decreased. However, the juvenile was able to maintain a higher rate of photosynthesis at comparable low water potentials than the adult which indicates that the juvenile is the more drought tolerant of the two. Leaves of the juvenile also retain water better than those of the adult under moderately windy conditions. When plants were grown in a wind tunnel at wind speeds of up to 12 m secˉ¹ stomatal closure (as measured using a leaf diffusion resistance meter) occurred at lower wind speeds in the juvenile than the adult leaves. The results obtained during this investigation thus support the hypothesis that the small-leafed divaricating juvenile of Pennantia is better adapted to a dry, exposed habitat than is the large-leafed orthotropic adult

Decriminalizing Delinquency: The Effect of Raising the Age of Majority on Juvenile Recidivism

In the last decade, a number of states have expanded the jurisdiction of their juvenile courts by increasing the maximum age to 18. Proponents argue that these expansions reduce crime by increasing access to the beneficial features of the juvenile justice system. Critics counter that the expansions risk increasing crime by reducing deterrence. In 2010, Illinois raised the maximum age for juvenile court for offenders who commit a misdemeanor. By examining the effect of this law on juvenile offenders in Chicago, this paper provides the first empirical estimates of the consequences of recent legislative activity to raise the age of criminal majority. Applying a difference-in-differences design with multiple control groups, we find little evidence of an effect. Our results suggest that—contrary to the expectations of both advocates and opponents— increasing the maximum age for juvenile court does not affect juvenile recidivism

Juveniles Taken into Custody Research Program: Estimating the Prevalence of Juvenile Custody by Race and Gender (FOCUS)

When attempting to answer questions such as what proportion of our nation's juvenile population will be taken into custody of state juvenile corrections systems or how does the probability of those same juveniles differ for males and females and for different ethnic and racial groups, a measure of "prevalence" must be applied. Prevalence refers to the estimated proportion of the at-risk population of juveniles based on several age, race, and sex population subgroups, who are likely to be committed to the custody of state juvenile corrections systems by age 18. Until recently, there was no national data reporting system that recorded on an individual basis, the number and characteristics of youth admitted to juvenile corrections facilities. With the newly implemented State Juvenile Corrections System Reporting Program, we can now generate estimates of prevalence rates for state custody. These results clearly indicate that the problem of minority over-representation in our juvenile custody population is much greater than previously thought and intensifies the already urgent need to comprehend the problem and address this apparent disparity