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1.
Ecol Evol ; 14(6): e11536, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38932952

ABSTRACT

In recent years, illegal felling of and damage to the incense tree Aquilaria sinensis (Lour.) Spreng. have been reported in Hong Kong. Their native populations are under increasingly severe threat. Therefore, the development of a standard and efficient method to classify and document wounds on vulnerable trees is urgently needed for conservation purposes. In this study, photogrammetry was used to document wounds in A. sinensis through 3D modeling. A total of 752 wound records from 484 individual A. sinensis trees from Hong Kong were included to establish a new wound classification system. Our major findings include a novel standardized procedure for photogrammetric documentation and a wound classification system. The results of this study will facilitate A. sinensis conservation, by enhancing wound documentation and information transfer to law enforcement and education.

2.
Oecologia ; 198(4): 1057-1072, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35380273

ABSTRACT

Because the diet of many herbivorous insects is restricted to closely related taxa with similar chemistry, intercropping with diverse plant communities may reduce both pest populations and reliance on chemical pesticides in agroecosystems. We tested whether the effectiveness of intercropping against herbivorous insects depends on the phylogenetic relatedness of neighboring crops, using butternut squash (Cucurbita moschata) as a focal crop species in a series of different intercropping combinations. We found that increased phylogenetic divergence of neighboring plants could reduce abundance of herbivorous insects, but the effect was only detectable mid-season. In addition, we tested two hypothesized mechanisms for a negative association between phylogenetic distance of neighboring plants and reduced herbivore populations: one, we tested using Y-tube olfactometer and choice cage trials whether diverse volatile cues impede host-plant location by the dominant pest of butternut squash in our experiment, striped cucumber beetle Acalymma vittatum. Two, we recorded predator and parasitoid abundance relative to crop phylodiversity to test whether diverse crops support larger natural-enemy populations that can better control pest species. Our results, however, did not support either hypothesis. Striped cucumber beetles preferentially oriented toward non-host-plant volatiles, and predator populations more often decreased with phylodiversity than increased. Thus, the mechanisms driving associations in the field between phylogenetic divergence and herbivore populations remain unclear.


Subject(s)
Coleoptera , Cucurbita , Animals , Herbivory , Phylogeny , Plants
3.
J Insect Physiol ; 130: 104210, 2021 04.
Article in English | MEDLINE | ID: mdl-33610542

ABSTRACT

Eurosta solidaginis males produce large amounts of putative sex pheromone compared to other insect species; however, neither the site of pheromone production nor the release mechanism has been characterized. We compared E. solidaginis males and females, focusing on sexually dimorphic structures that are known to be involved in pheromone production in other tephritid species. Morphological and chemical analyses indicated that the rectum and pleural epidermis are involved in male E. solidaginis pheromone production, storage, or emission. We detected large quantities of pheromone in the enlarged rectum, suggesting that it stores pheromone for subsequent release through the anus. However, pheromone might also discharge through the pleural cuticle with the involvement of unusual pleural attachments of the tergosternal muscles, which, when contracted in males, realign specialized cuticular surface elements and expose less-sclerotized areas of cuticle. In males, pheromone components were also detected in epidermal cells of the pleuron. These cells were 60-100 times larger in mature males than in females and, to our knowledge, are the largest animal epithelial cells ever recorded. Furthermore, because these large cells in males are multinucleated, we presume that they develop through somatic polyploidization by endomitosis. Consequently, the pheromone-associated multinuclear pleural epidermal cells of Eurosta solidaginis may provide an interesting new system for understanding polyploidization.


Subject(s)
Epidermal Cells/cytology , Polyploidy , Sex Attractants/biosynthesis , Tephritidae/physiology , Animals , Female , Male , Tephritidae/cytology
4.
Insects ; 11(2)2020 Feb 18.
Article in English | MEDLINE | ID: mdl-32085627

ABSTRACT

Pollinator nutritional ecology provides insights into plant-pollinator interactions, coevolution, and the restoration of declining pollinator populations. Bees obtain their protein and lipid nutrient intake from pollen, which is essential for larval growth and development as well as adult health and reproduction. Our previous research revealed that pollen protein to lipid ratios (P:L) shape bumble bee foraging preferences among pollen host-plant species, and these preferred ratios link to bumble bee colony health and fitness. Yet, we are still in the early stages of integrating data on P:L ratios across plant and bee species. Here, using a standard laboratory protocol, we present over 80 plant species' protein and lipid concentrations and P:L values, and we evaluate the P:L ratios of pollen collected by three bee species. We discuss the general phylogenetic, phenotypic, behavioral, and ecological trends observed in these P:L ratios that may drive plant-pollinator interactions; we also present future research questions to further strengthen the field of pollination nutritional ecology. This dataset provides a foundation for researchers studying the nutritional drivers of plant-pollinator interactions as well as for stakeholders developing planting schemes to best support pollinators.

5.
BMC Plant Biol ; 19(1): 209, 2019 May 21.
Article in English | MEDLINE | ID: mdl-31113387

ABSTRACT

BACKGROUND: By sensing environmental cues indicative of pathogens or herbivores, plants can "prime" appropriate defenses and deploy faster, stronger responses to subsequent attack. Such priming presumably entails costs-else the primed state should be constitutively expressed-yet those costs remain poorly documented, in part due to a lack of studies conducted under realistic ecological conditions. We explored how defence priming in goldenrod (Solidago altissima) influenced growth and reproduction under semi-natural field conditions by manipulating exposure to priming cues (volatile emissions of a specialist herbivore, Eurosta solidaginis), competition between neighbouring plants, and herbivory (via insecticide application). RESULTS: We found that primed plants grew faster than unprimed plants, but produced fewer rhizomes, suggesting reduced capacity for clonal reproduction. Unexpectedly, this effect was apparent only in the absence of insecticide, prompting a follow-up experiment that revealed direct effects of the pesticide esfenvalerate on plant growth (contrary to previous reports from goldenrod). Meanwhile, even in the absence of pesticide, priming had little effect on herbivore damage levels, likely because herbivores susceptible to the primed defences were rare or absent due to seasonality. CONCLUSIONS: Reduced clonal reproduction in primed plants suggest that priming can entail significant costs for plants. These costs, however, may only become apparent when priming cues fail to provide accurate information about prevailing threats, as was the case in this study. Additionally, our insecticide data indicate that pesticides or their carrier compounds can subtly, but significantly, affect plant physiology and may interact with plant defences.


Subject(s)
Herbivory , Solidago/physiology , Tephritidae/physiology , Volatile Organic Compounds/metabolism , Animals , Cues , Random Allocation , Rhizome/growth & development , Rhizome/physiology , Solidago/growth & development
6.
Int J Syst Evol Microbiol ; 66(9): 3329-3336, 2016 09.
Article in English | MEDLINE | ID: mdl-27257031

ABSTRACT

Two bacterial strains, HKU54T and HKU55, were isolated from the oral cavity of two Chinese cobras (Naja atra) in Hong Kong. 16S rRNA gene sequence analysis revealed 100 % sequence identity between HKU54T and HKU55, and the two strains shared 99.0 % sequence identities with Tsukamurella inchonensis ATCC 700082T. The two strains had unique biochemical profiles distinguishable from closely related species of the genus Tsukamurella. DNA-DNA hybridization confirmed that they belonged to the same species (≥92.1±7.9 % DNA-DNA relatedness) but were distinct from all other known species of the genus Tsukamurella (≤52.6±5.3 % DNA-DNA relatedness). Chemotaxonomic and morphological analyses of the two strains also demonstrated results consistent with their classification in the genus Tsukamurella. The DNA G+C contents of strains HKU54T and HKU55 were 69.2±1.5 mol% and 69.2±1.3 mol% (mean±sd; n=3) respectively. A novel species, Tsukamurella serpentis sp. nov., is proposed to accommodate strains HKU54T and HKU55, with HKU54T (=JCM 31017T=DSM 100915T) designated as the type strain.


Subject(s)
Actinomycetales/classification , Elapidae/microbiology , Mouth/microbiology , Phylogeny , Actinomycetales/genetics , Actinomycetales/isolation & purification , Animals , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Fatty Acids/chemistry , Hong Kong , Nucleic Acid Hybridization , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
7.
PLoS One ; 11(6): e0155433, 2016.
Article in English | MEDLINE | ID: mdl-27249787

ABSTRACT

The abundance of sperm relative to eggs selects for males that maximize their number of mates and for females that choose high quality males. However, in many species, males exercise mate choice, even when they invest little in their offspring. Sexual cannibalism may promote male choosiness by limiting the number of females a male can inseminate and by biasing the sex ratio toward females because, while females can reenter the mating pool, cannibalized males cannot. These effects may be insufficient for male choosiness to evolve, however, if males face low sequential encounter rates with females. We hypothesized that sexual cannibalism should facilitate the evolution of male choosiness in group living species because a male is likely to encounter multiple receptive females simultaneously. We tested this hypothesis in a colonial orb-weaving spider, Cyrtophora citricola, with a high rate of sexual cannibalism. We tested whether mated females would mate with multiple males, and thereby shift the operational sex ratio toward females. We also investigated whether either sex chooses mates based on nutritional state and age, and whether males choose females based on reproductive state. We found that females are readily polyandrous and exhibit no mate choice related to male feeding or age. Males courted more often when the male was older and the female was younger, and males copulated more often with well-fed females. The data show that males are choosier than females for the traits we measured, supporting our hypothesis that group living and sexual cannibalism may together promote the evolution of male mate choice.


Subject(s)
Cannibalism , Sexual Behavior, Animal , Spiders/physiology , Animals , Female , Male
8.
BMC Infect Dis ; 16: 74, 2016 Feb 10.
Article in English | MEDLINE | ID: mdl-26861696

ABSTRACT

BACKGROUND: Long-term outcomes in non-HIV immunocompromised patients with disseminated Mycobacterium avium complex (dMAC) infections are unknown and the need for post-treatment secondary prophylaxis against MAC is uncertain in this setting. The objective of this study was to determine the need of continuing secondary anti-MAC prophylaxis in non-HIV patients after completing treatment of the primary dMAC episode. METHODS: We conducted a ten-year multi-center analysis of non-HIV immunosuppressed patients with dMAC infections in Hong Kong. RESULTS: We observed sixteen patients with dMAC during the study period of which five (31 %) were non-HIV immunosuppressed patients. In the non-HIV immunosuppressed group, three patients completed a treatment course without secondary prophylaxis, one patient received azithromycin-based secondary prophylaxis and one patient was still receiving therapy for the first dMAC episode. All the three patients who completed treatment without being given secondary prophylaxis developed recurrent dMAC infection requiring retreatment. CONCLUSIONS: In view of the high rate of dMAC infection recurrence in non-HIV immunocompromised patients following treatment completion, our data support long-term anti-MAC suppression therapy after treatment of the first dMAC infection episode in immunocompromised non-HIV patients, as is recommended for patients with advanced HIV. Tests of cell mediated immune function need to be evaluated to guide prophylaxis discontinuation in non-HIV patients.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Antibiotic Prophylaxis , Azithromycin/therapeutic use , Immunocompromised Host , Mycobacterium avium Complex , Mycobacterium avium-intracellulare Infection/drug therapy , Adult , Aged , Aged, 80 and over , Female , HIV Infections , Hong Kong , Humans , Male , Mycobacterium avium-intracellulare Infection/prevention & control , Recurrence
9.
Biol Rev Camb Philos Soc ; 89(2): 427-49, 2014 May.
Article in English | MEDLINE | ID: mdl-24171917

ABSTRACT

While most spiders are solitary and opportunistically cannibalistic, a variety of social organisations has evolved in a minority of spider species. One form of social organisation is subsociality, in which siblings remain together with their parent for some period of time but disperse prior to independent reproduction. We review the literature on subsocial and maternal behaviour in spiders to highlight areas in which subsocial spiders have informed our understanding of social evolution and to identify promising areas of future research. We show that subsocial behaviour has evolved independently at least 18 times in spiders, across a wide phylogenetic distribution. Subsocial behaviour is diverse in terms of the form of care provided by the mother, the duration of care and sibling association, the degree of interaction and cooperation among siblings, and the use of vibratory and chemical communication. Subsocial spiders are useful model organisms to study various topics in ecology, such as kin recognition and the evolution of cheating and its impact on societies. Further, why social behaviour evolved in some lineages and not others is currently a topic of debate in behavioural ecology, and we argue that spiders offer an opportunity to untangle the ecological causes of parental care, which forms the basis of many other animal societies.


Subject(s)
Behavior, Animal/physiology , Maternal Behavior , Social Behavior , Spiders/physiology , Animals , Biological Evolution , Female , Spiders/genetics
10.
Pediatr Infect Dis J ; 32(12): 1396-9, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23817339

ABSTRACT

We did a retrospective review of children with Mycoplasma pneumoniae infection hospitalized from March 2010 to March 2013. Mycoplasma-resistant M. pneumoniae constituted 70% of the total M. pneumoniae-associated community-acquired pneumonia. Doxycycline was significantly more effective than macrolide for treatment of Mycoplasma-resistant M. pneumoniae-associated community-acquired pneumonia in terms of achievement of rapid defervescence within 24 hours.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Community-Acquired Infections/drug therapy , Community-Acquired Infections/microbiology , Doxycycline/therapeutic use , Macrolides/therapeutic use , Pneumonia, Mycoplasma/drug therapy , Pneumonia, Mycoplasma/microbiology , Adolescent , Anti-Bacterial Agents/pharmacology , Child , Child, Preschool , Community-Acquired Infections/epidemiology , Drug Resistance, Bacterial , Female , Fever/microbiology , Hong Kong/epidemiology , Humans , Macrolides/pharmacology , Male , Mycoplasma pneumoniae/drug effects , Pneumonia, Mycoplasma/epidemiology , Retrospective Studies
12.
Proc Natl Acad Sci U S A ; 105(33): 11818-22, 2008 Aug 19.
Article in English | MEDLINE | ID: mdl-18689677

ABSTRACT

A decrease in the surface area per unit volume is a well known constraint setting limits to the size of organisms at both the cellular and whole-organismal levels. Similar constraints may apply to social groups as they grow in size. The communal three-dimensional webs that social spiders build function ecologically as single units that intercept prey through their surface and should thus be subject to this constraint. Accordingly, we show that web prey capture area per spider, and thus number of insects captured per capita, decreases with colony size in a neotropical social spider. Prey biomass intake per capita, however, peaks at intermediate colony sizes because the spiders forage cooperatively and larger colonies capture increasingly large insects. A peaked prey biomass intake function would explain not only why these spiders live in groups and cooperate but also why they disperse only at large colony sizes, thus addressing both sociality and colony size range in this social spider. These findings may also explain the conspicuous absence of social spiders from higher latitudes and higher elevations, areas that we have previously shown to harbor considerably fewer insects of the largest size classes than the lowland tropical rainforests where social spiders thrive. Our findings thus illustrate the relevance of scaling laws to the size and functioning of levels of organization above the individual.


Subject(s)
Cooperative Behavior , Predatory Behavior/physiology , Spiders/physiology , Animals
13.
Am Nat ; 170(5): 783-92, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17926299

ABSTRACT

To the extent that geography correlates with particular environmental parameters, the geographical distribution of phylogenetically related social and nonsocial organisms should shed light on the conditions that lead to sociality versus nonsociality. Social spiders are notorious for being concentrated in tropical regions of the world, occupying a set of habitats more restricted than those available to the phylogenetic lineages in which they occur. Here we document a parallel pattern involving elevation in the spider genus Anelosimus in America and describe the biology of a newly discovered social species found at what appears to be the altitudinal edge of sociality in the genus. We show that this is a cooperative permanent-social species with highly female-biased sex ratios but colonies that are one to two orders of magnitude smaller than those of a low-elevation congener of similar body size. We suggest that the absence of subsocial Anelosimus species in the lowland rain forest may be due to an increased probability of maternal death in this habitat due to greater predation and/or precipitation, while absence of a sufficient supply of large insects at high elevations or latitudes may restrict social species to low- to midelevation tropical moist forests. We refer to these as the "maternal survival" and "prey size" hypotheses, respectively, and suggest that both in combination may explain the geographical distribution of sociality in the genus.


Subject(s)
Social Behavior , Spiders/physiology , Animals , Cooperative Behavior , Ecuador , Feeding Behavior , Female , Geography , Male , Population Dynamics , Sex Ratio , Spiders/classification
14.
Phytother Res ; 20(9): 725-31, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16775808

ABSTRACT

CKBM is an herbal formula composed of five Chinese medicinal herbs (Panax ginseng, Schisandra chinensis, Fructus crataegi, Ziziphus jujuba and Glycine max) supplemented with processed Saccharomyces cerevisiae. It has been demonstrated that CKBM is capable of triggering the release of IL-6 and TNFalpha from human peripheral blood mononuclear cells. In this report, T-lymphocytic Sup-T1 cells and B-lymphocytic Ramos cells were utilized as cellular models to investigate how CKBM regulates intracellular signaling as well as the production of cytokines. CKBM stimulated the three major subgroups of mitogen-activated protein kinase (i.e. ERK, JNK and p38) in Sup-T1 cells, but only triggered the activation of ERK and p38 in Ramos cells. The induction of mitogen-activated protein kinases (MAPK) activations varied with the duration of treatment, as well as with the dosage of CKBM. In terms of cytokine production, treatment of CKBM alone did not trigger the release of IL-1beta and IFNgamma, but it suppressed the LPS-induced IFNgamma production from both Sup-T1 cells and Ramos cells. In view of the therapeutic effects of traditional Chinese medicines in inflammatory and autoimmune disorders, the results suggest that CKBM may exhibit its immuno-modulatory effects by regulating intracellular signaling as well as cytokine production in different lymphocytic cell types.


Subject(s)
Drugs, Chinese Herbal/pharmacology , Interferon-gamma/drug effects , Lymphocyte Activation/drug effects , Lymphocytes/drug effects , MAP Kinase Signaling System/drug effects , Mitogen-Activated Protein Kinases/drug effects , Cell Line , Dose-Response Relationship, Drug , Humans , Lipopolysaccharides , Time Factors
15.
Am J Chin Med ; 34(2): 263-78, 2006.
Article in English | MEDLINE | ID: mdl-16552837

ABSTRACT

Radix Glycyrrhizae (RG) is a medicinal herb extensively utilized in numerous Chinese medical formulae for coordinating the actions of various components in the recipes and strengthening the body functions. In this report, we demonstrate that the aqueous extract of Radix Glycyrrhizae is capable of stimulating the c-Jun N-terminal kinase and p38 subgroups of mitogen-activated protein kinases (MAPKs), and the nuclear factor-kappaB (NFkappaB) in Jurkat T-lymphocytes. The activation magnitudes of MAPKs and NFkappaB were dose-dependent (EC(50) approximately 1 mg/ml) and time-dependent (maximal around 15-30 minutes). Stimulations of MAPKs and NFkappaB were not associated with changes in intracellular Ca(2+) mobilization. Similar activation profiles of MAPK and NFkappaB were obtained from THP-1 monocytes treated with the extract. In terms of chemotactic activity, the SDF-induced chemotaxis of Jurkat cells and THP-1 cells were inhibited by RG extract at 1-10 mg/ml, while a lower RG concentration (0.1-0.3 mg/ml) potentiated the SDF-induced chemotaxis for the former, but not the latter cell type. Given the fact that MAPKs and NFkappaB are important signaling intermediates for lymphocyte activities, our results suggest that Radix Glycyrrhizae may contain active constituents capable of modulating immuno-responses through various intracellular signaling pathways.


Subject(s)
Mitogen-Activated Protein Kinases/metabolism , Monocytes/drug effects , NF-kappa B/metabolism , Plant Extracts/pharmacology , Chemotaxis/drug effects , Humans , Jurkat Cells , Monocytes/enzymology , Monocytes/metabolism , Phosphorylation
16.
Biol Pharm Bull ; 28(9): 1645-50, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16141532

ABSTRACT

CKBM is an herbal formula composed of five Chinese medicinal herbs (Panax ginseng, Schisandra chinensis, Fructus crataegi, Ziziphus jujube and Glycine Max) supplemented with processed Saccharomyces cerevisiae. Previous studies have demonstrated that CKBM is capable of triggering the release of IL-6 and TNFalpha from human peripheral blood mononuclear cells, and its anti-tumorigenic activity has been demonstrated in nude mice with gastric cancer. In this report, we utilized the THP-1 monocytic cell line as a cellular model to investigate how CKBM regulates the intracellular signaling of monocytes and the subsequent release of the produced cytokines. In terms of mitogen-activated protein kinase (MAPK) cascades, CKBM (20%) had no significant effect on ERK, but was linked to an inhibitory effect on JNK and a stimulatory effect on p38 MAPK. The differential responsiveness of JNK and p38 was dependent on the duration of treatment, as well as on the dosage of CKBM. Treatment of CKBM alone induced the release of IL-10 and IFNgamma, but not IL-1beta, IL-4, IL-6 and TNFbeta, while increase of intracellular Ca2+ concentration by A23187 triggered the release of IL-10 only. Interestingly, A23187 synergized with the activities of CKBM-treated THP-1 cells in terms of IL-1beta and IFNgamma production, while the IL-10 production showed no synergistic relationship between CKBM and A23187. This A23187-induced synergism was associated with a dose-dependent character towards CKBM administration. In view of the intracellular Ca2+ elevation during monocyte activation, our results suggest that CKBM can serve as a promoting agent for modulating the functions of monocytes.


Subject(s)
Cytokines/metabolism , Drugs, Chinese Herbal/pharmacology , Immunologic Factors , Mitogen-Activated Protein Kinases/metabolism , Monocytes/metabolism , Calcimycin/pharmacology , Cell Line , Cytokines/biosynthesis , Dose-Response Relationship, Drug , Drug Combinations , Interferon-gamma/metabolism , Interleukin-10/metabolism , Ionophores/pharmacology , NF-kappa B/metabolism , Phosphorylation , Signal Transduction/drug effects , Trans-Activators/physiology
17.
Planta Med ; 71(7): 634-9, 2005 Jul.
Article in English | MEDLINE | ID: mdl-16041649

ABSTRACT

Essential oils are a major active constituent found in many Chinese medicinal herbs. Here, we demonstrate that two components of essential oils, carvacrol and eugenol, dose-dependently trigger intracellular Ca2+ mobilization in Jurkat T-cells and THP-1 monocytic cells. Both carvacrol and eugenol are also capable of stimulating the active phosphorylation of the p38 subgroup of mitogen-activated protein kinases (MAPKs) in both cell types. However, carvacrol selectively activated the ERK subgroup in Jurkat T-cells, and stimulated the JNK subgroup in THP-1 monocytic cells. Eugenol treatment was not linked to ERK or JNK activation in either cell type. EC50 values for the induction of Ca2+ mobilization and MAPK activation were around 10 - 30 microM for both carvacrol and eugenol. Our results suggest that these essential oil components may act as effective agents to modulate the functions of immuno-responsive cells via different intracellular signaling pathways.


Subject(s)
Calcium/metabolism , Drugs, Chinese Herbal/pharmacology , Eugenol/pharmacology , Monoterpenes/pharmacology , Phytotherapy , Plants, Medicinal , Cymenes , Dose-Response Relationship, Drug , Drugs, Chinese Herbal/administration & dosage , Drugs, Chinese Herbal/therapeutic use , Eugenol/administration & dosage , Eugenol/therapeutic use , Humans , Jurkat Cells/drug effects , Monocytes/drug effects , Monoterpenes/administration & dosage , Monoterpenes/therapeutic use , p38 Mitogen-Activated Protein Kinases/metabolism
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