Better alone? A demographic case study of the hemiparasite Castilleja tenuiflora (Orobanchaceae): A first approximation

Castilleja tenuiflora is a facultative root hemiparasitic plant that has colonized a disturbed lava field in central Mexico. To determine the effects of hemiparasitism on the population dynamics of the parasite, we identified a set of potential hosts and quantified their effects on the vital rates of C. tenuiflora during 2016–2018. Connections between the roots of the hemiparasite and the hosts were confirmed with a scanning electron microscope. Annual matrices considering two conditions (with and without potential hosts) were built based on vital rates for each year, and annual stochastic finite rate growth rates (λ_s) were calculated. Plants produced more reproductive structures with hosts than without hosts. A Life Table Response Experiment (LTRE) was performed to compare the contributions of vital rates between conditions. We identified 19 species of potential hosts for this generalist hemiparasite. Stochastic lambda with hosts λ_s = 1.02 (CI = 0.9999, 1.1) tended to be higher than without them λ_s = 0.9503 (CI = 0.9055, 0.9981). The highest elasticity values correspond to survival. LTRE indicated that the most important parameters are survival and fecundity; the total contribution of fecundity (0.0192) to the difference in growth was three times lower than that of survival (0.0603). Piqueria trinervia was the most abundant host, and C. tenuiflora had a higher lambda with it than with other species. Individuals can grow alone, but hosts can have a positive effect on the vital parameters of C. tenuiflora and on λ.     

Correction to: Relative Importance of Climate,Soil and Plant Functional Traits During the Early Decomposition Stage of Standardized Litter

Ecosystems - A correction to this paper has been published: https://doi.org/10.1007/s10021-021-00614-y     

Passive Internalization of Bioactive β-Casein Peptides into Phospholipid (POPC) Bilayers. Free Energy Landscapes from Unbiased Equilibrium MD Simulations at μs-Time Scale

Food Biophysics - Absorption of bioactive peptides in the intestinal epithelium take place in the apical or the basolateral tight junctions of the cells. Depending on the peptide size and...     

Diversity of trypanosomes in humans and cattle in the HAT foci Mandoul and Maro,Southern Chad—A matter of concern for zoonotic potential?

BackgroundAfrican trypanosomes are parasites mainly transmitted by tsetse flies. They cause trypanosomiasis in humans (HAT) and animals (AAT). In Chad, HAT/AAT are endemic. This study investigates the diversity and distribution of trypanosomes in Mandoul, an isolated area where a tsetse control campaign is ongoing, and Maro, an area bordering the Central African Republic (CAR) where the control had not started.Methods717 human and 540 cattle blood samples were collected, and 177 tsetse flies were caught. Trypanosomal DNA was detected using PCR targeting internal transcribed spacer 1 (ITS1) and glycosomal glyceraldehyde-3 phosphate dehydrogenase (gGAPDH), followed by amplicon sequencing.ResultsTrypanosomal DNA was identified in 14 human samples, 227 cattle samples, and in tsetse. Besides T. b. gambiense, T. congolense was detected in human in Maro. In Mandoul, DNA from an unknown Trypanosoma sp.-129-H was detected in a human with a history of a cured HAT infection and persisting symptoms. In cattle and tsetse samples from Maro, T. godfreyi and T. grayi were detected besides the known animal pathogens, in addition to T. theileri (in cattle) and T. simiae (in tsetse). Furthermore, in Maro, evidence for additional unknown trypanosomes was obtained in tsetse. In contrast, in the Mandoul area, only T. theileri, T. simiae, and T. vivax DNA was identified in cattle. Genetic diversity was most prominent in T. vivax and T. theileri.ConclusionTsetse control activities in Mandoul reduced the tsetse population and thus the pathogenic parasites. Nevertheless, T. theileri, T. vivax, and T. simiae are frequent in cattle suggesting transmission by other insect vectors. In contrast, in Maro, transhumance to/from Central African Republic and no tsetse control may have led to the high diversity and frequency of trypanosomes observed including HAT/AAT pathogenic species. Active HAT infections stress the need to enforce monitoring and control campaigns. Additionally, the diverse trypanosome species in humans and cattle indicate the necessity to investigate the infectivity of the unknown trypanosomes regarding their zoonotic potential. Finally, this study should be widened to other trypanosome hosts to capture the whole diversity of circulating trypanosomes.     

Integration of Biological Control and Native Seeding to Restore Invaded Plant Communities

Disturbed natural areas frequently experience invasion by introduced plant species that can reduce native biodiversity. Biological control can suppress these introduced species, but without restoration another introduced species can invade. Integration of biological control with concurrent revegetation can both aid in weed reduction via interspecific plant competition and establish a restored native plant community. This 3‐year study investigated an integrated approach to controlling the introduced annual Mile‐a‐minute weed (Persicaria perfoliata [L.] H. Gross [Polygonaceae]) using the biocontrol weevil Rhinoncomimus latipes Korotyaev (Coleoptera: Curculionidae) and restoration planting using a native seed mix. A fully factorial design tested weevils and seeding, separately and together, using insecticide to eliminate weevils. The weevils together with the native seed mix reduced P. perfoliata percent cover in 2009 and 2010, and peak seed cluster production in 2010, compared to the insecticide ? no seed control treatment. Persicaria perfoliata final dry biomass was reduced by 75% in 2010 and by 57% in 2011 in the weevils plus seed treatment compared to the control, with weevils having the greatest effect in 2010 and the seed treatment having the greatest impact in 2011. Results suggest an additive effect of biocontrol and seeding in suppressing P. perfoliata. Seeded treatments also developed the highest native plant species richness and diversity, comprised of spontaneous recolonization in addition to species from the seed mix. Results support the use of integrated management of this invasive weed, with suppression through biological control and native revegetation together helping prevent reinvasion while restoring native plant biodiversity.     

Inhibition of acetylcholinesterase by two arylderivatives: 3a-Acetoxy-5H-pyrrolo(1,2-a) (3,1)benzoxazin-1,5-(3aH)-dione and cis-N-p-Acetoxy-phenylisomaleimide

Two arylderivatives, 3a-Acetoxy-5H-pyrrolo(1,2-a) (3,1)benzoxazin-1,5-(3aH)-dione 3 and cis-N-p-Acetoxy-phenylisomaleimide 4, were synthesized from anthranilic acid and para-aminophenol, respectively. The inhibitory effects of these compounds on acetylcholinesterase (AChE) activity were evaluated in vitro as well as by docking simulations. Both compounds showed inhibition of AChE activity (K_i = 4.72 ± 2.3 μM for 3 and 3.6 ± 1.8 μM for 4) in in vitro studies. Moreover, they behaved as irreversible inhibitors and made π–π interaction with W84 and hydrogen bonded with S200 and Y337 according to experimental data and docking calculations. The docking calculations showed ΔG bind (kcal/mol) of ? 9.22 for 3 and ? 8.58 for 4. These two compounds that can be use as leads for a new family of anti-Alzheimer disease drugs.     

Palladium-Catalyzed Animation of 6-Chloropurine. Synthesis of N6-Substituted Adenosine Analogues

Abstract

Room-temperature treatment of persilylated 6-chloro-9-β-D-ribofuranosyl-purine with a variety of aliphatic and aromatic amines, in the presence of Pd₂(dba)₃, BINAP and base, leads to N⁶-substituted adenosine analogues in fair to good yields. Coupling of chloropurine with a chiral aziridinyl diester is applied in the synthesis of a potential adenylosuccinate lyase inhibitor.     

Adenocarcinoma of the Ileocolic Junction and Multifocal Hepatic Sarcomas in an Aged Rhesus Macaque (Macaca mulatta)

An aged male rhesus macaque in our colony had decreased appetite and a loss of interest in behavioral testing. CBC analysis revealed a regenerative, microcytic, hypochromic anemia with thrombocytosis, consistent with iron deficiency. A fecal occult blood test was positive. Ultrasound imaging revealed numerous, vascularized focal liver lesions that suggested metastases. The macaque''s appetite continued to decrease, and he became more lethargic. At this point, the investigator elected to euthanize the macaque. At necropsy, the ileocolic junction was white and abnormally thickened, and the liver was pale tan with approximately 18 discrete white masses randomly scattered throughout the hepatic parenchyma. Histologically, the mass at the ileocolic junction was identified as an intestinal adenocarcinoma, whereas the liver masses were confirmed to be undifferentiated hepatic sarcomas. This case report describes a rhesus macaque that had 2 unrelated primary neoplasms. A review of the literature indicates that this rhesus macaque is the first reported to have an adenocarcinoma of the ileocolic junction and multiple hepatic sarcomas simultaneously.Rhesus macaques (Macaca mulatta) are genetically similar to humans, have a similar aging phenotype at approximately 3 times the rate of those in humans, and develop spontaneous cancers similar to those in humans.³⁶ In humans, gastrointestinal carcinomas are relatively common, but most of these lesions arise in the colon and rectum with only a small percentage in the small intestine and ileum.^4,12,15,18 Although the ileocolic junction is considered a common site for intestinal adenocarcinomas in aged rhesus macaques, this tumor has also been found in the duodenum, jejunum, distal ileum, cecum, and colon.^{6,13,21-23,25,39} Intestinal adenocarcinomas also occur in aged cynomologus macaques (Macaca fasicularis),³⁹ cotton-top marmosets (Saguinus oedipus),^6,10 common marmosets (Callithrix jacchus),^6,27 and a squirrel monkey (Saimiri sciureus).²⁴ Cotton-top marmosets often develop adenocarcinomas of the colon, including the cecum–colon, and rectum.^6,10 Common marmosets have been reported to develop adenocarcinomas of the small intestine.^6,27 Adenocarcinoma of the cecum in a squirrel monkey has been reported.²⁴Spontaneous hepatic tumors unrelated to carcinogenic factors, such as aflatoxin B1,³³ occur only rarely in nonhuman primates. In the United States, primary malignant hepatic tumors in humans are rare, and fewer than 1% are reported to be hepatic sarcomas.^1,16,40 Review of the nonhuman primate literature revealed reports of hepatic cholangiocarcinoma in a 25-y-old male capuchin monkey (Cebus albifrons),⁷ hepatocellular carcinoma in a 24-y-old male squirrel monkey (Saimiri boliviensis)⁵ and in a female squirrel monkey (Saimiri sciureus) older than 13 y,²⁸ and hepatocellular carcinoma and cholangiocarcinoma in an African green monkey (Cercopithecus aethiops).³⁴ Spontaneous hepatocellular carcinomas were reported to occur in 2 adolescent male cynomologus macaques younger than 5 y.³¹ Hepatic hemangiosarcoma was diagnosed in 3-y-old female rhesus macaque,²⁶ and hepatic cholangiocarcinoma was found in a rhesus macaque that also had an intestinal adenocarcinoma.³⁹The aged male rhesus macaque (Macaca mulatta) in the current case study was found to have adenocarcinoma of the ileocolic junction and multiple, random, discrete neoplasms in the liver, which were identified as undifferentiated sarcomas. No metastases from the intestinal adenocarcinoma were detected, but neoplastic cells similar to those of the undifferentiated hepatic cells were identified in an intestinal artery. The frequency of multiple tumor types in aged nonhuman primates is relevant to the use of older animals in research.