Nectar cardenolides and floral volatiles mediate a specialized wasp pollination system.

Specialization in plant pollination systems can arise from traits that function as filters of flower visitors. This may involve chemical traits such as floral volatiles that selectively attract favoured visitors and non-volatile nectar constituents that selectively deter disfavoured visitors through taste or longer-term toxic effects or both. We explored the functions of floral chemical traits in the African milkweed Gomphocarpus physocarpus, which is pollinated almost exclusively by vespid wasps, despite having nectar that is highly accessible to other insects such as honeybees. We demonstrated that the nectar of wasp-pollinated G. physocarpus contains cardenolides that had greater toxic effects on Apis mellifera honeybees than on Vespula germanica wasps, and also reduced feeding rates by honeybees. Behavioural experiments using natural compositions of nectar compounds showed that these interactions are mediated by non-volatile nectar chemistry. We also identified volatile compounds with acetic acid as a main component in the floral scent of G. physocarpus that elicited electrophysiological responses in wasp antennae. Mixtures of these compounds were behaviourally effective for attraction of V. germanica wasps. The results show the importance of both volatile and non-volatile chemical traits as filters that lead to specialization in plant pollination systems.

Neural and behavioural responses of the pollen-specialist bee Andrena vaga to Salix odours.

An effective means of finding food is crucial for organisms. Whereas specialized animals select a small number of potentially available food sources, generalists use a broader range. Specialist (oligolectic) bees forage on a small range of flowering plants for pollen and use primarily olfactory and visual cues to locate their host flowers. So far, however, little is known about the specific cues oligoleges use to discriminate between hosts and non-hosts and how floral scent compounds of hosts and non-hosts are processed in the bees' olfactory system. In this study, we recorded physiological responses of the antennae (electroantennographic detection coupled to gas chromatography; GC-EAD) and in the brain (optical imaging; GC imaging), and studied host-finding behaviour of oligolectic Andrena vaga bees, a specialist on Salix plants. In total, we detected 37 physiologically active compounds in host and non-host scents. 4-Oxoisophorone, a common constituent in the scent of many Salix species, evoked strong responses in the antennal lobe glomeruli of A. vaga, but not the generalist honeybee Apis mellifera. The specific glomerular responses to 4-oxoisophorone in natural Salix scents reveals a high degree of specialization in A. vaga for this typical Salix odorant component. In behavioural experiments, we found olfactory cues to be the key attractants for A. vaga to Salix hosts, which are also used to discriminate between hosts and non-hosts, and A. vaga demonstrated a behavioural activity for 4-oxoisophorone. A high sensitivity to floral scents enables the specialized bees to effectively find flowers and it appears that A. vaga bees are highly tuned to 4-oxoisophorone at a very low concentration.

Floral traits are associated with the quality but not quantity of heterospecific stigmatic pollen loads.

BACKGROUND: In flowering communities, plant species commonly share pollinators and therefore plant individuals receive heterospecific pollen (HP). However, the patterns of HP transfers can deviate from patterns of plant-pollinator visitations. Although flower-visitor interactions are known to be mediated by floral traits, e.g. floral size or nectar tube depth, the explanatory power of these traits for HP transfer patterns remains elusive. Here, we have explored pollen transfer patterns at three sites in Southern Germany on three dates (early, mid and late summer). At the plant level, we tested whether flower abundance and floral traits are correlated with HP reception and donation. At the community level, we determined whether flower and bee diversity are correlated with network modularity and whether floral traits explain the module affiliation of plant species. We collected the stigmas of flowering plant species, analysed HP and conspecific pollen (CP) loads and measured floral traits, flower and bee diversity. RESULTS: Our results show that the degree and intensity of HP reception or donation at the plant level do not correlate with floral traits, whereas at the community level, the module affiliation of who is sharing pollen with whom is well-explained by floral traits. Additionally, variation in network modularity between communities is better explained by plant diversity and abundance than by bee diversity and abundance. CONCLUSIONS: Overall, our results indicate that floral traits that are known to mediate flower-visitor interactions can improve our understanding of qualitative HP transfer but only provide limited information about the quantity of HP transfer, which more probably depends on other floral traits, flower-visitor identity or community properties.

Urinary bladder cancer risk factors in an area of former coal, iron, and steel industries in Germany.

This study was performed to investigate the frequency of bladder cancer in patients with an occupational history such as underground hard coal mining and/or painting after the structural change in the local industry. A total of 206 patients with bladder cancer and 207 controls were enlisted regarding occupational and nonoccupational bladder cancer risk factors by questionnaire. The phase II enzymes N-acetyltransferase 2 (NAT2), glutathione S-transferases M1 (GSTM1), and T1 (GSTT1) and the single nucleotide polymorphism (SNP) rs11892031[A/C] reported to be associated with bladder cancer in genome-wide association studies were genotyped. The bladder cancer risk in varnishers and underground hard coal miners was increased as previously shown in a study in this area performed in the 1980s. The occupation of a car mechanic was associated with a significantly elevated bladder cancer risk and higher in the case of underground hard coal miners even though the mine was closed in 1987. The frequency of GSTM1 negative genotype was comparable in cases and controls (53% versus 54%). In the case of NAT2, the slow NAT2 genotype was more frequent (62% versus 58%) and ultra-slow NAT2 genotype (NAT2*6A and/or *7B alleles only) was 23% versus 15%. An occupational history of a varnisher or an underground hard coal miner remains a risk factor for bladder cancer occurrence. Data indicate that in the case of bladder cancer, GSTM1 is a susceptibility factor related to environmental and/or occupational exposure.

Polymorphisms of xenobiotic metabolizing enzymes in bladder cancer patients of the Semmelweis University Budapest, Hungary.

Polymorphic xenobiotic metabolizing enzymes such as N-acetyltransferase 2 (NAT2) or glutathione S-transferase M1 (GSTM1) are known to modulate bladder cancer risk. As no apparent data were available from Hungary, a former member of the eastern European economic organization, a study was performed in Budapest. In total, 182 bladder cancer cases and 78 cancer-free controls were investigated by questionnaire. Genotypes of NAT2, GSTM1, GSTT1, rs1058396 and rs17674580 were determined by standard methods. Current smokers' crude odds ratio (OR) (3.43) and former smokers crude OR (2.36) displayed a significantly increased bladder cancer risk. The risk rose by a factor of 1.56 per 10 pack years. Exposure to fumes was associated with an elevated bladder cancer risk (23% cases, 13% controls). Sixty-four % of the cases and 59% of controls were slow NAT2 acetylators. It was not possible to establish a particular impact of NAT2*6A and *7B genotypes (15 cases, 8%, 5 controls, 7%). GSTT1 exerted no marked influence on bladder cancer (negative 21% cases vs. 22% controls). The portion of GSTM1 negative bladder cancer patients was increased (63% cases vs. 54% controls). The SLC14A1 SNPs rs1058396[AG/GG] and the nearby rs17674580[CT/TT] occurred more frequently in cases (79% and 68%) than controls (77% and 55%). The portion of GSTM1 negative bladder cancer patients is comparable with portions reported from other industrialized areas like Lutherstadt Wittenberg/Germany (58%), Dortmund/Germany (70%), Brescia/Italy (66%) or an occupational case-control series in Germany (56%). Data indicate that GSTM1 is a susceptibility factor for environmentally triggered bladder cancer rather than for smoking-mediated bladder cancer.

Occupational risk factors for prostate cancer in an area of former coal, iron, and steel industries in Germany. Part 2: results from a study performed in the 1990s.

Currently, there is no established occupational risk factor for prostate cancer. However, in the 1980s, a hospital-based case-control study in the greater Dortmund area showed an elevated risk for hard coal miners and, based on few cases, for painters and varnishers. Therefore, approximately 10 yr later, a similar study regarding prostate cancer was performed in this area. In total, 292 patients with prostate cancer who underwent radical prostatectomy and 313 controls who underwent transurethral resection of a benign prostatic hyperplasia were investigated by questionnaire. All of them were operated on between 1995 and 1999. This study showed a decreased risk for prostate cancer in hard coal miners (odds ratio [OR] = 0.67, 95% confidence interval [CI] = 0.44-1.03). Occupational exposures related to an elevated risk for prostate cancer were exposures to combustion products (20% cases vs. 11% controls), colorants and dyes (19 vs. 13%), and cutting fluids (8 vs. 6%). The different prostate cancer risks for underground coal miners in two studies with a time interval of approximately 10 yr are striking. Factors to be discussed are the introduction of prostate-specific antigen (PSA) screening for prostate cancer and investigation of cases that underwent radical prostatectomy, where the disease in general is locally confined. Working conditions in the local underground coal mines improved over time but did not change markedly in the period of interest. In essence, the present study does not corroborate an elevated prostate cancer risk in former underground hard coal miners from the greater Dortmund area.

Occupational risk factors for relapse-free survival in bladder cancer patients.

The influence of occupational risk factors on bladder cancer development is well investigated. However, studies on the influence on bladder cancer prognosis are rare. Therefore, it was of interest to investigate the time to first relapse in the follow-ups of three case-control series from Dortmund, Neuss, and Lutherstadt Wittenberg, Germany. Relapse-free survival of in total 794 urinary bladder cancer patients (Dortmund 174, Neuss 407, Lutherstadt Wittenberg 213) was derived from medical records. Cox regression models were used to determine the impact of profession and exposure to bladder carcinogens if the risk factor was present in at least four cases. One or several relapses were observed in 416 cases (52%). Median time to first relapse was 0.94 yr. Ten professions were observed in at least 4 patients. No significant associations were found. However, workers in the leather industry (n = 4), printing industry (n = 4), transportation (n = 43), and chemical industry (n = 40) and locksmiths/mechanics (n = 44) showed shorter relapse-free times. No trend to shorter relapse-free time was observed for miners (n = 42), agriculturists (n = 18), painters/lacquerers (n = 21), colorant production and processing workers (n = 7), foundry workers (n = 5), and persons exposed to aromatic amines (n = 45). Although the follow-up comprised nearly 800 cases, data on occupations and exposures of interest were not sufficient to obtain significant results. However, first results indicated potential associations that are worth further investigations.

Floral Trait Preferences of Three Common wild Bee Species.

The interaction between bees and flowering plants is mediated by floral cues that enable bees to find foraging plants. We tested floral cue preferences among three common wild bee species: Lasioglossum villosulum, Osmia bicornis, and Bombus terrestris. Preferences are well studied in eusocial bees but almost unknown in solitary or non-eusocial generalist bee species. Using standardized artificial flowers altered in single cues, we tested preferences for color hue, achromatic contrast, scent complexity, corolla size, and flower depth. We found common attractive cues among all tested bees. Intensively colored flowers and large floral displays were highly attractive. No preferences were observed in scent complexity experiments, and the number of volatiles did not influence the behavior of bees. Differing preferences were found for color hue. The specific behaviors were probably influenced by foraging experience and depended on the flower choice preferences of the tested bee species. In experiments testing different flower depths of reward presentation, the bees chose flat flowers that afforded low energy costs. The results reveal that generalist wild bee species other than well-studied honeybees and bumblebees show strong preferences for distinct floral cues to find potential host plants. The diverse preferences of wild bees ensure the pollination of various flowering plants.

Perception of floral volatiles involved in host-plant finding behaviour: comparison of a bee specialist and generalist.

Specialist and generalist bees use olfactory and visual cues to find and recognise flowering plants. Specialised (oligolectic) bees rely on few host plants for pollen collection. These bee species are suggested to use specific volatiles, but it is unknown whether they have dedicated adaptations for these particular compounds compared to bees not specialised on the same plants. In the present study, we investigated the perception of host odorants and its neuronal substrate with regard to host-plant finding behaviour in oligolectic bees. We reconstructed the antennal lobes (AL) in the Salix specialist, Andrena vaga, and counted about 135 glomeruli and thereby less than the approximately 160 in honeybees. Using calcium imaging experiments to measure neural activity in the bee brain, we recorded odorant-evoked activity patterns in the AL of A. vaga and, for comparison, in the generalist honeybee, Apis mellifera. Our physiological experiments demonstrated that A. vaga bees were particularly sensitive to 1,4-dimethoxybenzene, a behaviour-mediating odorant of Salix host flowers. We found more sensitive glomeruli in the specialised bees as compared to generalist honeybees. This neural adaptation might allow oligolectic A. vaga bees to effectively locate host plants from distances.

From Tick to Test: A Comprehensive Review of Tick-Borne Disease Diagnostics and Surveillance Methods in the United States.

Tick-borne diseases (TBDs) have become a significant public health concern in the United States over the past few decades. The increasing incidence and geographical spread of these diseases have prompted the implementation of robust surveillance systems to monitor their prevalence, distribution, and impact on human health. This comprehensive review describes key disease features with the geographical distribution of all known tick-borne pathogens in the United States, along with examining disease surveillance efforts, focusing on strategies, challenges, and advancements. Surveillance methods include passive and active surveillance, laboratory-based surveillance, sentinel surveillance, and a One Health approach. Key surveillance systems, such as the National Notifiable Diseases Surveillance System (NNDSS), TickNET, and the Tick-Borne Disease Laboratory Network (TBDLN), are discussed. Data collection and reporting challenges, such as underreporting and misdiagnosis, are highlighted. The review addresses challenges, including lack of standardization, surveillance in non-human hosts, and data integration. Innovations encompass molecular techniques, syndromic surveillance, and tick surveillance programs. Implications for public health cover prevention strategies, early detection, treatment, and public education. Future directions emphasize enhanced surveillance networks, integrated vector management, research priorities, and policy implications. This review enhances understanding of TBD surveillance, aiding in informed decision-making for effective disease prevention and control. By understanding the current surveillance landscape, public health officials, researchers, and policymakers can make informed decisions to mitigate the burden of (TBDs).

An arthropod deterrent attracts specialised bees to their host plants.

Many bee species are adapted to just a few specific plants in order to collect pollen (oligolecty). To reproduce successfully, it is important for oligolectic bees to find and recognise the specific host flowers. In this study, we investigated the role of floral volatiles used by an oligolectic bee to recognise its host plants. We compared the attractiveness of natural and synthetic scent samples of host flowers to foraging-naïve and -experienced Hoplitis adunca (Megachilidae) bees that are specialised on Echium and Pontechium (Boraginaceae) plants. The investigations showed that naïve H. adunca females are attracted to 1,4-benzoquinone. During their lifetime, bees learn additional floral cues while foraging on host flowers. In contrast to naïve ones, experienced H. adunca females use, in addition to 1,4-benzoquinone, other compounds to recognise their host plants. 1,4-Benzoquinone is an uncommon floral compound only known from the host plants of H. adunca, and is therefore ideally suited to be used as a plant-specific recognition cue. Several arthropods use this compound to deter insect predators. Therefore, 1,4-benzoquinone as an attractant in Echium flowers may have evolved from a primary function as a defensive compound against insect herbivores.

Artificial Nesting Hills Promote Wild Bees in Agricultural Landscapes.

The availability of nesting resources influences the persistence and survival of bee communities. Although a positive effect of artificial nesting structures has frequently been shown for aboveground cavity-nesting wild bees, studies on below ground-nesting bees are rare. Artificial nesting hills designed to provide nesting habitats for ground-nesting bees were therefore established within the BienABest project in 20 regions across Germany. Wild bee communities were monitored for two consecutive years, accompanied by recordings of landscape and abiotic nest site variables. Bee activity and species richness increased from the first to the second year after establishment; this was particularly pronounced in landscapes with a low cover of semi-natural habitat. The nesting hills were successively colonized, indicating that they should exist for many years, thereby promoting a species-rich bee community. We recommend the construction of nesting hills on sun-exposed sites with a high thermal gain of the substrate because the bees prefer south-facing sites with high soil temperatures. Although the soil composition of the nesting hills plays a minor role, we suggest using local soil to match the needs of the local bee community. We conclude that artificial nesting structures for ground-nesting bees act as a valuable nesting resource for various bee species, particularly in highly degraded landscapes. We offer a construction and maintenance guide for the successful establishment of nesting hills for bee conservation.

θ-γ Cross-Frequency Transcranial Alternating Current Stimulation over the Trough Impairs Cognitive Control.

Cognitive control is a mental process, which underlies adaptive goal-directed decisions. Previous studies have linked cognitive control to electrophysiological fluctuations in the θ band and θ-γ cross-frequency coupling (CFC) arising from the cingulate and frontal cortices. However, to date, the behavioral consequences of different forms of θ-γ CFC remain elusive. Here, we studied the behavioral effects of the θ-γ CFC via transcranial alternating current stimulation (tACS) designed to stimulate the frontal and cingulate cortices in humans. Using a double-blind, randomized, repeated measures study design, 24 healthy participants were subjected to three active and one control CFC-tACS conditions. In the active conditions, 80-Hz γ tACS was coupled to 4-Hz θ tACS. Specifically, in two of the active conditions, short γ bursts were coupled to the delivered θ cycle to coincide with either its peaks or troughs. In the third active condition, the phase of a θ cycle modulated the amplitude of the γ oscillation. In the fourth, control protocol, 80-Hz tACS was continuously superimposed over the 4-Hz tACS, therefore lacking any phase specificity in the CFC. During the 20 min of stimulation, the participants performed a Go/NoGo monetary reward-based and punishment-based instrumental learning task. A Bayesian hierarchical logistic regression analysis revealed that relative to the control, the peak-coupled tACS had no effects on the behavioral performance, whereas the trough-coupled tACS and, to a lesser extent, amplitude-modulated tACS reduced performance in conflicting trials. Our results suggest that cognitive control depends on the phase specificity of the θ-γ CFC.