RECENT ADVANCES IN VETERINARY ENTOMOLOGY1

The advances during the last 15 years in our knowledge of the biology and control of arthropod pests of livestock and vectors of animal disease agents exceed those made in any similar period in past history. Before 1942 we relied mainly on rotenone, pyrethrum, the thiocyanates, and the arseni­cals for control of lice, ticks, mites, biting flies, and cattle grubs. While ef­fective against some pests under certain conditions, these materials were not practical for wide-scale use and did not meet the public demand for better insecticides. Today we have highly effective and low-cost insecticides such as DDT, lindane, TDE, toxaphene, methoxychlor, chlordane, and syner­gized pyrethrum for control of livestock insects. Their use has saved the live­ stock grower many millions of dollars annually and has benefited the con­ sumer by making more and better animal products available. Of almost equal importance to the development of the new insecticides are the contributions made to our knowledge of the biology and habits of several livestock insects and their transmission of agents of animal diseases. Many new ideas and approaches to studies on insect biology and control have been developed during the last few years. A good example of this is the unique method for the control of screw-worms by release of sterilized male flies over an area. The sterile males mate with the native females, but the eggs are infertile and thus reduce the numbers of screw-worms. Another ex­ ample of new trends is the promising research with insecticides that can be given internally to livestock for destruction of external pests. These studies will be discussed in detail in the following pages. Although great progress has been made in the use of insecticides, two disturbing factors have arisen to cause worry as to the future efficiency of chemical means of control. The first is the increasing and widespread de­velopment of resistance of insects to insecticides, particularly to the chlo­rinated hydrocarbons. House flies have developed such a high degree of re­sistance to DDT and related materials that satisfactory control is impossible in most areas. Organic phosphorus insecticides have so far performed in a creditable manner in controlling house flies, but there are indications that these chemicals may eventually fail. As yet no reports on resistance of horn flies, horse flies, deer flies, stable flies, sheep keds, or lice of livestock have appeared

Influence of Co and Ni addition on the magnetocaloric effect in Fe88−2xCoxNixZr7B4Cu1 soft magnetic amorphous alloys

We have studied the magnetocaloric effect in a series of Fe88−2xCoxNixZr7B4Cu1Fe88−2xCoxNixZr7B4Cu1alloys. The partial substitution of Fe by Co and Ni leads to a monotonic increase in the Curie temperature(TC)(TC) of the alloys from 287 K for x=0x=0 to 626 K for x=11x=11. The maximum magnetic entropy change (ΔSpkM)(ΔSMpk) at an applied field of 1.5 T, shows a value of 1.98 J K−1 kg−11.98 J K−1 kg−1 for x=8.25x=8.25. The refrigerant capacity (RC) has maximum values near 166 J kg−1166 J kg−1 (for x=0x=0 and 2.75). These values place the present series of alloys among the best magnetic refrigerant materials, with an RC ∼40%∼40% larger than Gd5Si2Ge1.9Fe0.1Gd5Si2Ge1.9Fe0.1 and ∼15%∼15% larger than Fe-based amorphousalloys

Magnetocaloric effect and critical exponents of Fe77Co 5.5Ni5.5Zr7B4Cu1: A detailed study

The critical exponents of the alloy have been determined with the Kouvel–Fisher method to predict the field dependence of the magnetic entropy change DSM . The nonlinear fit of DSM ðHÞ to a power law provides a field exponent in perfect agreement with the predictions of the relevant scaling laws using the obtained critical exponent values. It is shown that possible discrepancies between these two methods for determining the field dependence of DSM might arise due to a poor resolution in the temperature of the experiments

Optimization of the refrigerant capacity in multiphase magnetocaloric materials

The refrigerant capacity (RC) of magnetocaloric materials can be enhanced using multiphase materials or composites, which expand the temperature range over which a significant magnetic entropy change can be obtained. Numerical simulations show that by controlling the parameters of the composite (the fraction of the different phases and their Curie temperatures) improvements of RC of ∼83% are possible. The maximum applied field plays a crucial, nonmonotonic, role in the optimization. As a proof of concept, it is shown that the combination of two Fe88−2xCoxNixZr7B4Cu1 alloys produces an enhancement in RC of ∼37%, making it ∼92% larger than that of Gd5Si2Ge1.9Fe0.

Last-male sperm precedence in Rhynchophorus ferrugineus (Olivier): observations in laboratory mating experiments with irradiated males

The Red PalmWeevil (RPW)Rhynchophorus ferrugineus(Olivier 1790) is an invasive pest from southeastern Asia and Melanesia that in the last 30 years has spread widely in the Middle East and Mediterranean Basin. Its stem-boring larvae cause great damage to several palm species of the Arecaceae family, many of which are economically important for agricultural and ornamental purposes. Therefore, great attention has recently been focused in studying this species to identify sustainable and effective eradication strategies, such as sterile insect technique (SIT). The rapid spread of RPW is associated with its high reproductive success. To evaluate the suitability of a SIT strategy, particular physiological and behavioral aspects of RPW reproduction, such as the presence of polyandry and post-copulatory sperm selection mechanisms, were investigated. To determine paternity of progeny from multiply mated females, double-crossing experiments were carried out confining individual females with either a wild-type male or a γ-irradiated male (Co-60). Fecundity and fertility of females were scored to evaluate post-copulatory sperm selection. Results showed that progeny were almost exclusively produced by the sperm of the second male, suggesting that a last-male sperm precedence is expressed at high levels in this species, and providing interesting insights for an area-wide RPW management strategy such as the SIT

Car-Truck Crashes in the National Motor Vehicle Crash Causation Survey

The National Motor Vehicle Crash Causation Survey (NMVCCS) provided in-depth investigative data on pre-crash factors and other characteristics of 5,471 crashes involving light passenger vehicles (“cars”). Within the dataset, 199 crashes, representing 79,721 crashes nationally, were collisions between cars and large trucks. These 199 car-truck crashes constitute the second largest U.S. truck in-depth crash investigation dataset ever compiled, but its findings have not previously been published. NMVCCS is a significant source of information about the genesis of car-truck crashes. This includes variables relating to crash configurations, critical reasons, associated factors, and conditions of occurrence. Findings supplement and generally corroborate those from the Large Truck Crash Causation Study. However, NMVCCS data are more recent and represent a wider range of crash severities. Cars were more likely than trucks to be the encroaching/precipitating vehicle in car-truck collisions. Overall, 71.0% of assigned Critical Reasons (CRs) were to the car. Cars were more likely to be outof-control prior to impact and to violate rights-of-way. Associated, contributing factors relating to driver impairment or stress were noted more frequently for car drivers. Trucks were more likely to be assigned vehicle-related CRs and associated factors, however. Nationally, about 80% of truck-related fatalities occur in car-truck crashes. Understanding their genesis is essential for the development of effective countermeasures

Naturalistic Driving Events: No Harm, No Foul, No Validity

This paper challenges the validity of vehicle-based Naturalistic Driving (ND) Safety Critical Events (SCEs) in relation to injury and fatal crashes. It asserts that mixed SCE datasets have no known or likely representativeness in relation to serious crashes and are likely invalid in regard to their causal factors. This argument is made in the context of ND attempts to associate truck driver Hours-of-Service parameters and safety. But the argument generally applies to other mixed SCE datasets. In part, the challenge is to a monolithic “Heinrich Triangle.” Crashes are heterogeneous, both “horizontally” within any severity strata and “vertically” across strata. Serious crashes account for the vast majority of human harm, and are very different from minor crashes. Yet all crashes have, and are defined by, tangible external consequences. In contrast, SCEs are defined by driver maneuvers. Their datasets contain almost no crashes, let alone harm. As such, they are not properly part of the “triangle.” Mixed SCE datasets are collections of multiple, disparate driver maneuvers chosen and defined by researchers. They are thus contrived, not analytically derived from the phenomenon of importance, serious crashes. No valid quantitative inferences about the genesis of crash harm can be made from such datasets. This deficiency does not invalidate all ND applications, however. And SCE and real crash datasets could be linked by systematic sampling and case weighting based on objective crash characteristics

Analyses of density-dependent effects are needed to understand how and when Wolbachia can control dengue vectors

Releases of Wolbachia-infected mosquitoes have been shown to be an effective method of controlling Aedes aegypti, the main vector of dengue fever, in Australia. A study in BMC Biology from Penelope Hancock and others shows that incorporation of density-dependent effects into population models can provide major improvements in understanding how and when the infected populations can become established

Evidence and Dimensions of Commercial Driver Differential Crash Risk

This paper highlights evidence from several instrumented vehiclestudies that crash risk varies significantly among commercial truck drivers, andalso cites findings from surveys of fleet safety managers and other experts on thetopic of individual differences in commercial driver crash risk. Within varioussubject groups, 10-15% of the drivers typically account for 30-50% of the crashrisk. This pattern is seen in measures of driver errors associated with crashes andalso in measures of driver drowsiness. The evidence also suggests, but does notyet prove, that these individual differences are long-term. To the extent that theseindividual differences are long-term, they may be considered personal traits. Thispaper conceptualizes driver risk factors, provides illustrative examples ofdifferential individual risk within groups of drivers, identifies driver factorsthought to be most associated with crash risk, and considers the opportunities forimproved commercial driving safety presented by differential crash risk