Spin-selectivity effect of G-quadruplex DNA molecules.

Chirality-induced spin selectivity has been attracting extensive interest in recent years and is demonstrated in a variety of chiral molecules, all of which arise from inherent molecular chirality. Here, we first propose a theoretical model to study the spin-dependent electron transport along guanine-quadruplex (G4) DNA molecules, connected to two nonmagnetic electrodes, by considering the molecule-electrode contact and weak spin-orbit coupling. Our results indicate that the G4-DNA molecular junctions exhibit pronounced spin-selectivity effect, and the asymmetric contact-induced external chirality, instead of the inherent molecular chirality, dominates their spin filtration efficiency. Furthermore, the spin-selectivity effect is robust against the disorder and hold in a wide range of model parameters. These results could be checked by charge transport measurements and provide an alternative way to improve the spin-selectivity effect of chiral nanodevices.

Accelerated PARAFAC-Based Channel Estimation for Reconfigurable Intelligent Surface-Assisted MISO Systems.

To achieve fast and accurate channel estimation of reconfigurable intelligent surface (RIS)-assisted multiple-input single-output (MISO) systems, we propose an accelerated bilinear alternating least squares algorithm (ABALS) based on parallel factor decomposition. Firstly, we build a tensor model of the received signal, and expand it to obtain the unfolded forms of the model. Secondly, we derive the expression of the estimation problem of two channels based on the unfolded forms to transform the problem into a cost function problem. Furthermore, we solve the cost function problem by introducing a simpler iterative optimization constraint and linear interpolation. Finally, we provide a strategy on the receiver design based on the feasibility conditions discussed in this paper, which can guarantee the uniqueness of the channel estimation problem. Simulation results show that the proposed algorithm can obtain a faster estimation speed and less iteration steps than the alternating least squares (ALS) algorithm, and the accuracy of the two algorithms is very close.

Beamforming Design for Cooperative Intelligent Reflecting Surface-Assisted mmWave Communication.

In order to investigate the effect of cooperative Intelligent Reflecting Surface (IRS) in improving spectral efficiency, this paper explores the joint design of active and passive beamforming based on a double IRS-assisted model. First, considering the maximum power constraint of the active vector and the unit modulus constraint of the cooperative passive vector, we establish the non-linear and non-convex optimization problem of multi-user maximization weighted sum rate (WSR). Then, we propose an alternating optimization (AO) algorithm to design the active vector and the cooperative passive vector based on fractional programming (FP) and successive convex approximations (SCA). In addition, we conduct a study on the optimization of the passive reflection vector under discrete phase shift. The simulation results show that the proposed beamforming scheme of double IRS-assisted model performs better than the conventional single IRS-assisted model.

Th17 cell differentiation induced by cytopathogenic biotype BVDV-2 in bovine PBLCs.

BACKGROUND: Bovine viral diarrhea virus (BVDV) is a major pathogen that causes bovine viral diarrhea/mucosal disease (BVD-MD), which has become a global infectious disease due to its wide spread and the lack of effective treatment. The process of BVDV infection is complex. Once infected, host immune cells are activated and modulated. As a major immune cell, peripheral blood lymphocyte cells (PBLCs) are the primary target of BVDV. In order to further understand the mechanism of BVDV- host interaction, the expression profiles of host lymphocytes mRNAs associated with BVDV infection were investigated by transcriptomic sequencing analysis. RESULTS: The transcriptomic sequencing analysis was performed on bovine PBLCs infected with CP BVDV-2 GS2018 after 12 h of infection. Gene expression profiling demonstrated that 1052 genes were differentially expressed in GS2018 infected PBLCs compared with the control group. Of these genes, 485 genes were up-regulated and 567 were down-regulated. The 19 differential expressed genes (DEGs) were selected for validation using quantitative real-time PCR and the results were consistent with the results of RNA-Seq. Gene ontology enrichment and KEGG pathway analysis showed that 1052 DEGs were significantly enriched in 16 pathways, including cytokine-cytokine receptor interaction, IL17, PI3K-Akt, MAPK and TNF signaling pathway. PPI network analysis showed that IL17A, IFN-γ and TNF-α interacted with various proteins and may play crucial roles in BVDV-2 infection. Of note, we confirmed that GS2018 induced Th17 cell differentiation in PBLCs and persistently increased the expression levels of IL17A. In turn, the replication of GS2018 was inhibited by IL17A. CONCLUSION: In this study, the transcription changes of DEGs related to host immune responses in bovine PBLCs were caused by CP BVDV-2 infection. In particular, the effector molecules IL17A of Th17 cells were significantly up-regulated, which inhibited viral replication. These results will contribute to exploration and further understanding of the host immune response mechanism and interaction between host and BVDV-2.

Echinococcus shiquicus in Qinghai-Tibet plateau: population structure and confirmation of additional endemic areas.

Echinococcus shiquicus is currently limited to the Qinghai­Tibet plateau, a large mountainous region in China. Although the zoonotic potential remains unknown, progress is being made on the distribution and intermediate host range. In this study, we report E. shiquicus within Gansu and Qinghai provinces in regions located not only around the central areas but also the southeast edge of the plateau and describe their genetic relationship with previous isolates from the plateau. From 1879 plateau pikas examined, 2.39% (95% CI 1.79­3.18) were infected with E. shiquicus. The highest prevalence of 10.26% (4.06­23.58) was recorded in Makehe town, Qinghai province. Overall the prevalence was marginally higher in Qinghai (2.5%, CI 1.82­3.43) than in Gansu (2%, CI 1.02­3.89). The cox1 and nad1 genes demonstrated high and low haplotype and nucleotide diversities, respectively. The median-joining network constructed by the cox1­nad1 gene sequences demonstrated a star-like configuration with a median vector (unsampled haplotype) occupying the centre of the network. No peculiar distinction or common haplotype was observed in isolates originating from the different provinces. The presence of E. shiquicus in regions of the southeast and northeast edges of the Qinghai­Tibet plateau and high genetic variation warrants more investigation into the haplotype distribution and genetic polymorphism by exploring more informative DNA regions of the mitochondrial genome to provide epidemiologically useful insight into the population structure of E. shiquicus across the plateau and its axis.

Nurses in advanced roles as a strategy for equitable access to healthcare in the WHO Western Pacific region: a mixed methods study.

BACKGROUND: The Western Pacific region constitutes one-quarter of the world's population and has diverse health needs. While dialogue on and promotion of advanced practice nurses are ongoing, this study investigated the current responsibilities of nurses in advanced roles, future healthcare needs, and the implications of these components for nurses' professional development within the Western Pacific region. METHODS: This study employed three phases, a descriptive survey on the current status of nurses in advanced roles in the Western Pacific region, followed by a Delphi survey, and exploratory interviews. A total of 55 national experts with clinical, academic, and/or government-related backgrounds from 18 countries participated from December 2017 - December 2018. The descriptive survey via email to identify the status of nurses in advanced roles and a working definition was developed. This formed the basis for the Delphi survey, which identified key barriers and challenges for enhancing the development of nurses in advanced roles within the country (round 1) and for the region (rounds 2 and 3). Lastly, semi-structured individual interviews were conducted to identify strategies for establishing nurses in advanced roles to improve equitable access to healthcare. RESULTS: Thirty-seven roles and characteristics were identified and categorized for nurses performing advanced roles. Emergency care, critical care, elderly health, child health, and rural/remote communities were identified as fields with particular need for nurses in advanced roles in the Western Pacific region. Providing effective services, influencing government leadership, and advocating for health system sustainability were deemed necessary to improve equitable healthcare access. We found that nurses in advanced roles are not limited to clinical tasks within the hospital but are poised for active participation in primary healthcare, education/teaching, professional leadership, quality management, and research. CONCLUSIONS: Demand for nurses in advanced roles is high in the Western Pacific region and 15 items were identified across five core strategic areas to enhance development of nurses in advanced roles. Governmental-level recommendations include establishing legislative protection, improving systems for remuneration, strengthening supportive channels, and conducting national needs assessments.

The training contents, problems and needs of doctors in urban community health service institutions in China.

BACKGROUND: The Chinese government offered various types of training programs for strengthening the role of doctors working in community health service institutions (CHSIs). The study intended to investigate the current training programs and training needs of doctors nationally in urban CHSIs in China, and to provide propositions for training more qualified doctors in the future. METHODS: Total 3098 doctors in 192 urban CHSIs were chosen from 9 provinces (Hebei, Liaoning, Shandong, Zhejiang, Fujian, Hunan, Guangxi, Guizhou, Ningxia) and one municipality (Beijing) among 31 provinces in eastern, central, and western regions by stratified sampling methods in Mainland China. All doctors in the selected CHSIs were investigated in this study. We discharged 3073 questionnaires, and the response rate was 98.0%. Descriptive statistics were used to describe the characteristics, training contents, problems and needs of doctors. Differences in training contents, problems and needs between eastern, central and western regions were analyzed with chi-square tests. RESULTS: 49.3% of doctors in CHSIs had Bachelor's degree and beyond. 12.9% of doctors had senior professional titles. The most frequent training topics for the doctors in eastern, central and western regions were "basic clinical theory knowledge" (52.4%), "community health service competency" (59.6%), "clinical practice skills" (45.9%) respectively. The most serious problem for doctors was "insufficient training time" in eastern (36.8%), central (36.5%) and western (39.6%). The biggest knowledge need for doctors both in eastern (79.8%) and central region (79.1%) was "the updated international medical knowledge", in western region it was "the updated domestic medical knowledge" (73.2%). The biggest skill-related training need for doctors in eastern region (84.1%) and central region (82.6%) was "communication skills", and "diagnosis and differential diagnosis" in western region (78.2%). CONCLUSION: Government should design proper training contents according to the knowledge and skill needs of different design. Furthermore, a uniform, rigorous training and evaluation system focus on practicability should be established to promote community health service system in Mainland China.

Reliability and validity of the Chinese version of the Breathlessness Beliefs Questionnaire.

The aim of this article is to evaluate the reliability and validity of the Chinese version of the Breathlessness Beliefs Questionnaire (BBQ) for use among patients with respiratory diseases in China. The BBQ is an instrument for assessing specific dyspnoea-related fears and may have predictive value for chronic obstructive pulmonary disease outcomes beyond general anxiety measures. This instrument has not previously been translated into Chinese or tested in mainland China. This was a cross-sectional validation study with a 1-week test of reproducibility. A total of 252 Chinese patients with respiratory diseases recruited from pulmonary outpatient and inpatient departments completed the BBQ. Demographic characteristics, pulmonary function and degree of dyspnoea were also measured. Cronbach's α was 0.82 for the total BBQ score; 0.72 for the somatic focus subscale and 0.73 for the activity avoidance subscale. Test-retest reliability was satisfactory, with intraclass correlation coefficient scores for the BBQ overall and for each subscale ranging from 0.96 to 0.98 ( p < 0.001). After exploratory factor analyses, the Chinese version of the BBQ was found to be similar to the original Dutch version. The Chinese version of the BBQ is a reliable tool to assess dyspnoea-related fear in patients with respiratory diseases in mainland China.

Spin-dependent electron transport in protein-like single-helical molecules.

We report on a theoretical study of spin-dependent electron transport through single-helical molecules connected by two nonmagnetic electrodes, and explain the experiment of significant spin-selective phenomenon observed in α-helical protein and the contradictory results between the protein and single-stranded DNA. Our results reveal that the α-helical protein is an efficient spin filter and the spin polarization is robust against the disorder. These results are in excellent agreement with recent experiments [Mishra D, et al. (2013) Proc Natl Acad Sci USA 110(37):14872-14876; Göhler B, et al. (2011) Science 331(6019):894-897] and may facilitate engineering of chiral-based spintronic devices.

Cross-sectional survey of the disaster preparedness of nurses across the Asia-Pacific region.

Healthcare workers who have received disaster preparedness education are more likely to report a greater understanding of disaster preparedness. However, research indicates that current nursing curricula do not adequately prepare nurses to respond to disasters. This is the first study to assess Asia-Pacific nurses' perceptions about their level of disaster knowledge, skills, and preparedness. A cross-sectional survey was conducted with 757 hospital and community nurses in seven Asia-Pacific countries. Data were collected using the modified Disaster Preparedness Evaluation Tool. Participants were found to have overall low-to-moderate levels of disaster knowledge, skills and preparedness, wherein important gaps were identified. A majority of the variance in disaster preparedness scores was located at the level of the individual respondent, not linked to countries or institutions. Multilevel random effects modelling identified disaster experience and education as significant factors of positive perceptions of disaster knowledge, skills, and management. The first step toward disaster preparedness is to ensure frontline health workers are able to respond effectively to disaster events. The outcomes of this study have important policy and education implications.

Gene-guided identifications of a structure-chimeric cyclotide viphi I from Viola philippica: Potential functions against cadmium and nematodes.

The cyclic peptides, cyclotides, are identified mostly with 29-31-aa (amino acid residues) but rarely with ≥ 34-aa in plants. Viola philippica is a well-known medicinal plant but a rare metallophyte with cyclotides. A hypothesis was hence raised that the potential novel 34-aa cyclotide of Viola philippica would clearly broaden the structural and functional diversities of plant cyclotides. After homology-cloning the cyclotide precursor gene of VpCP5, a 34-aa cyclotide (viphi I) was identified to be larger than 22 other known cyclotides in V. philippica. It had a chimeric primary structure, due to its unusual loop structures (8 residues in loop 2 and 6 residues in loop 5) and aa composition (3 E and 5 R), by using phylogenetic analyses and an in-house cyclotide analysis tool, CyExcel_V1. A plasmid pCYC-viphi_I and a lab-used recombinant process were specially constructed for preparing viphi I. Typically, 0.12 or 0.25 mg ml-1 co-exposed viphi I could significantly remain cell activities with elevating Cd2+-exposed doses from 10-8 to 10-6 mol l-1 in MCF7 cells. In the model nematode Caenorhabditis elegans, IC50 values of viphi I to inhibit adult ratios and to induce death ratios, were 184.7 and 585.9 µg ml-1, respectively; the median lifespan of adult worms decreased from 14 to 2 d at viphi I doses ranging from 0.05 to 2 mg ml-1. Taken together, the newly identified viphi I exhibits functional potentials against cadmium and nematodes, providing new insights into structural and functional diversity of chimeric cyclotides in plants.

Engineering metal-carbide hydrogen traps in steels.

Hydrogen embrittlement reduces the durability of the structural steels required for the hydrogen economy. Understanding how hydrogen interacts with the materials plays a crucial role in managing the embrittlement problems. Theoretical models have indicated that carbon vacancies in metal carbide precipitates are effective hydrogen traps in steels. Increasing the number of carbon vacancies in individual metal carbides is important since the overall hydrogen trapping capacity can be leveraged by introducing abundant metal carbides in steels. To verify this concept, we compare a reference steel containing titanium carbides (TiCs), which lack carbon vacancies, with an experimental steel added with molybdenum (Mo), which form Ti-Mo carbides comprising more carbon vacancies than TiCs. We employ theoretical and experimental techniques to examine the hydrogen trapping behavior of the carbides, demonstrating adding Mo alters the hydrogen trapping mechanism, enabling hydrogen to access carbon vacancy traps within the carbides, leading to an increase in trapping capacity.

Collaborative care for patients with depression and diabetes mellitus: a systematic review and meta-analysis.

BACKGROUND: Diabetic patients with depression are often inadequately treated within primary care. These comorbid conditions are associated with poor outcomes. The aim of this systematic review was to examine whether collaborative care can improve depression and diabetes outcomes in patients with both depression and diabetes. METHODS: Medline, Embase, Cochrane library and PsyINFO were systematically searched to identify relevant publications. All randomized controlled trials of collaborative care for diabetic patients with depression of all ages who were reported by depression treatment response, depression remission, hemoglobin A1c (HbA1c) values, adherence to antidepressant medication and/or oral hypoglycemic agent were included. Two authors independently screened search results and extracted data from eligible studies. Dichotomous and continuous measures of outcomes were combined using risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs) either by fixed or random-effects models. RESULTS: Eight studies containing 2,238 patients met the inclusion criteria. Collaborative care showed a significant improvement in depression treatment response (RR = 1.33, 95% CI = 1.05-1.68), depression remission (adjusted RR = 1.53, 95% CI =1.11-2.12), higher rates of adherence to antidepressant medication (RR = 1.79, 95% CI = 1.19-2.69) and oral hypoglycemic agent (RR = 2.18, 95% CI = 1.61-2.96), but indicated a non-significant reduction in HbA1c values (MD = -0.13, 95% CI = -0.46-0.19). CONCLUSIONS: Improving depression care in diabetic patients is very necessary and important. Comparing with usual care, collaborative care was associated with significantly better depressive outcomes and adherence in patients with depression and diabetes. These findings emphasize the implications for collaborative care of diabetic patients with depression in the future.

The effects of motivational interviewing on hypertension management: A systematic review and meta-analysis.

OBJECTIVE: This systematic review aimed to examine the effects of motivational interviewing-based interventions on hypertension management. METHODS: Six databases were searched from inception to 25 July, 2022 for randomized controlled trials involving adults diagnosed with hypertension and including motivational interviewing in the treatment interventions. RESULTS: In total, 11 studies with 2121 participants were included. Compared with no or minimal additional intervention, motivational interviewing-based intervention showed greater reduction in systolic blood pressure (MD: -6.56, 95 % CI: -10.51, -2.62, P = 0.001) and diastolic blood pressure (MD: -3.75, 95 % CI: -4.92, -2.58, P < 0.001). Compared with the lower intensity intervention, motivational interviewing-based intervention produced statistically significant effect on reducing systolic blood pressure (MD: -2.72, 95 % CI: -5.34, -0.10, P = 0.040); while there was no significant effect on reducing diastolic blood pressure (MD: -0.47, 95 % CI: -2.21, 1.28, P = 0.600). Four out of six studies demonstrated medication adherence significantly improved following motivational interviewing-based intervention. Two studies included self-efficacy and quality of life, and inconsistent findings were observed. CONCLUSION: Motivational interviewing could be effective in improving blood pressure control among patients with hypertension. Future studies with more rigorous study designs should be conducted to confirm the effects of motivational interviewing on medication adherence and psychological well-being. PRACTICE IMPLICATIONS: Motivational interviewing could be applied as a promising intervention strategy among patients with hypertension.

Thermal dissipation of the quantum spin Hall edge states in HgTe/CdTe quantum well.

Quantum spin Hall effect is characterized by topologically protected helical edge states. Here we study the thermal dissipation of helical edge states by considering two types of dissipation sources. The results show that the helical edge states are dissipationless for normal dissipation sources with or without Rashba spin-orbit coupling in the system, but they are dissipative for spin dissipation sources. Further studies on the energy distribution show that electrons with spin-up and spin-down are both in their own equilibrium without dissipation sources. Spin dissipation sources can couple the two subsystems together to induce voltage drop and non-equilibrium distribution, leading to thermal dissipation, while normal dissipation sources cannot. With the increase of thermal dissipation, the subsystems of electrons with spin-up and spin-down evolve from non-equilibrium finally to mutual equilibrium. In addition, the effects of disorder on thermal dissipation are also discussed. Our work provides clues to reduce thermal dissipation in the quantum spin Hall systems.

Enhanced electron transport and self-similarity in quasiperiodic borophene nanoribbons with line defects.

Recent experiments have revealed multiple borophene phases of distinct lattice structures, suggesting that the unit cells of ν1/6 and ν1/5 boron sheets, namely α and ß chains, serve as building blocks to assemble into novel borophene phases. Motivated by these experiments, we present a theoretical study of electron transport along two-terminal quasiperiodic borophene nanoribbons (BNRs), with the arrangement of the α and ß chains following the generalized Fibonacci sequence. Our results indicate that the energy spectrum of these quasiperiodic BNRs is multifractal and characterized by numerous transmission peaks. In contrast to the Fibonacci model that all the electronic states should be critical, both delocalized and critical states appear in the quasiperiodic BNRs, where the averaged resistance saturates at the inverse of one conductance quantum for the delocalized states in the large length limit and contrarily exhibits a power-law dependence on the nanoribbon length for the critical states. Besides, the self-similarity is observed from the transmission spectrum, where the conductance curves overlap at different energy regions of two quasiperiodic BNRs of different Fibonacci indices and the resistance curves are analogous to each other at different energy scales of a single quasiperiodic BNR. These results complement previous studies on quasiperiodic systems where the multifractal energy spectrum and the self-similarity are observed by generating quasiperiodic potential energies, suggesting that borophene may provide an intriguing platform for understanding the structure-property relationships and exploring the physical properties of quasiperiodic systems.

Spin-selective transport of electrons in DNA double helix.

The experiment that the high spin selectivity and the length-dependent spin polarization are observed in double-stranded DNA [Science 331, 894 (2011)], is elucidated by considering the combination of the spin-orbit coupling, the environment-induced dephasing, and the helical symmetry. We show that the spin polarization in double-stranded DNA is significant even in the case of weak spin-orbit coupling, while no spin polarization appears in single-stranded DNA. Furthermore, the underlying physical mechanism and the parameter dependence of the spin polarization are studied.

Mutual referral: a survey of GPs in Beijing.

BACKGROUND: China has been engaged in the process of reforming its health care system recently. The government has attempted to rebuild the referral system to lower cost and enhance equity of the medical services. OBJECTIVE: This study was undertaken to evaluate the current status of mutual referral pilot programme, perceived factors that affect referral behaviour and changes that would improve the current referral process in Beijing. METHODS: Using a cross-sectional study design, we sent a postal questionnaire to 138 urban district community health service (CHS) centres in Beijing. Questions were chosen from a formal consensus process based on a nominal group technique. RESULTS: One hundred twenty-five of 138 (90.6%) CHS centres responded to the survey. Seventy-six (61.8%) CHS centres reported that the mutual referral system was feasible. Twenty-six (21.1%) CHS centres reported that the mutual referral programme was running smoothly. Uncertainties of diagnosis/management and access to particular medical specialty interest or skills were the two most common factors that were suggested as affecting referral behaviour. The presence of a dedicated department to accept referrals in hospitals and the use of referral guidelines were the most preferred choices as likely to improve the current referral process. CONCLUSIONS: Since a system of gatekeeper role by GPs at CHS organizations has not been established in Beijing, most CHS doctors agree that to ensure the smooth operation of referrals, a dedicated department should be assigned by hospitals to receive referred patients. Official guidelines on referral should be developed, and health authorities should strengthen their supervision of referrals.

Impact of the nurse-related information through social media use on undergraduate nursing students' professional identity in nursing: A mixed-methods study.

AIM: To understand the impact of nurse-related information, through social media usage on undergraduate nursing students' professional identity. BACKGROUND: Previous research has addressed professional knowledge and practice that affect the development of undergraduate nursing students' professional identities. As an increasingly crucial factor in the internet age, social media needs to be explored in-depth for its influence on the professional identity in nursing. DESIGN: Sequential explanatory mixed method was used in this study. METHODS: In this quantitative study, participants (N = 698) completed an e-questionnaire survey between June and July of 2020. The relationship between main variables was analyzed by linear regression using SPSS 20.0. Then, face-to-face semi-structured and audio-recorded interviews were carried out among participants (N = 16) between January and March of 2021. RESULTS: The quantitative findings indicated that the mean score of professional identity was 93.07 ± 11.96 in participants. The results of the linear regression showed that the year in school, whether nursing was the first choice, online time per day, frequency of reading official accounts related nursing on WeChat and appraisal of the online nurse-related information and so on explained 49.0 % of the variance in professional identity. Four major themes emerged from the qualitative study: 1) increased concern; 2) few and non-professional information; 3) encouraged by positive information; 4) limited impact of negative information. CONCLUSIONS: Nurse-related information on social media has the potential to have an impact on undergraduate nursing students' professional identity. Nursing educators should guide undergraduate nursing students to use social media appropriately and assist them in developing their professional identity with it.

PCR-RFLP assay confirms the existence of different mitochondrial lineages of Taenia hydatigena including a possible geographically restricted group.

Taenia hydatigena is a widespread tapeworm of canids (primarily dogs) that causes cysticercosis in ruminants (domestic and wild) and manifests as depression and weakness secondary to various hepatic damages and sometimes mortality in young animals, although, commonly encountered cases are asymptomatic. In most taeniids, genetic polymorphism has been found to impact host preferences, distribution, disease epidemiology and management. Recently, we identified two main mitochondrial lineages of T. hydatigena in China, and here, we examined the mitochondrial nad4-nad5 genes of T. hydatigena from China, Nigeria, Pakistan and Sudan to assess the intraspecies variation of isolates from these countries and also the distribution of the distinct mitochondrial groups. In addition to China, haplogroup B variant was found in Pakistan, while haplogroup A demonstrated a widespread distribution. We then designed a PCR-restriction fragment length polymorphism (PCR-RFLP) assay using XmiI (AccI) and RsaI (AfaI) restriction enzymes to differentiate members of both haplogroups. This result provides more molecular evidence supporting the existence of distinct mitochondrial variants of T. hydatigena. The epidemiological significance of these different mitochondrial groups remains to be explored further. The current PCR-RFLP assay offers a useful molecular approach for investigating the genetic population structure of T. hydatigena in enzootic regions and in identifying/discriminating the different mitochondrial groups (haplogroups A and B).