Search Results (151)

Pharomachrus mocinno breeds in the cloud forests of the El Triunfo Biosphere Reserve, and migrates annually for six months to elevations of 900–1600 m. On the Gulf slope, temperate forests were identified as habitats for migration, but the forests on the Pacific slope have not been similarly described. In this study we described the emergent properties and phenological behavior of the plant communities of five sites identified as migration habitats, in order to test if the number of fruit-bearing species is related to the migration period. At each site, 10,000 m² was sampled, for which PBH (perimeter at breast height) and the height of shrubs and trees were annotated, including the number of palms and ferns included. We identified 25 orders, 41 families, 71 genera, and 94 species; 86.6% of these species produce fleshy fruits or fruits with modified structures that are eaten by Quetzals. During the migration period, 25–43% of these species have fruits. Eight woody species included 49% of the total individuals, which produce Quetzals’ feeding resources. The sites differed in vertical structure, composition and diversity levels. The rarefaction curve indicated that the upper site (1600 m) required more sampling. We identified three plant communities that were distributed either in montane rain forest or in the temperate forest. Since nearly 84% of the plant species are listed in the IUCN (International Union for Conservation of Nature), these forests have an intrinsic importance. The number of fruit-bearing species did not differ between migration and breeding seasons (X² (1, N = 76) 0.57; p = 0.32. Lauraceae did not stand out for the number of fruit-bearing species in any of the migration sites. Full article

Background/Objectives: Recent evidence suggests that gut microbiota plays an important role in anxiety and stress-related disorders through interactions along the gut–brain axis. Our aim was to determine the microbiological diversity of intestinal microorganisms in individuals with acute and remission phases of PD when compared to healthy individuals. Another aim was also to analyze the differences in the metabolic pathways occurring in the intestinal microbiota of individuals from the three analyzed groups. Methods: A diagnosis was established using the Mini-International Neuropsychiatric Interview (M.I.N.I). The gut’s microbiota composition was analyzed through bacterial 16S rRNA gene sequencing (V1–V2 regions). The clinical evaluations included a BMI measurement, Short Form-36 Health Survey (SF-36), Hamilton Anxiety Scale (HAM-A), Montgomery–Åsberg Depression Rating Scale (MADRS), Columbia-Suicide Severity Rating Scale (C-SSRS), and State-Trait Anxiety Inventory (STAI). Results: We recruited 62 participants (31 PD and 31 controls). After conducting quality control filtering, data from 54 participants were analyzed (25 PD, 11 acute, 14 remission, and 29 controls). Observed richness was lower in the acute PD (63) group than in the control (74) and remission (66) (p = 0.038) groups, whereas the Shannon and Simpson indices and beta diversity (PERMANOVA) were not significantly different. The Ruminococcus gnavus group was enriched in acute PD; no other deconfounded differences in microbial composition were detected. Predicted functional differences were detected by edgeR only and included the pathways that are related to steroid biosynthesis and innate immune signaling. Conclusions: Distinct gut microbial signatures were associated with PD, implicating both the metabolic and inflammatory pathways in disease pathophysiology. Full article

Background: Magnolia alejandrae is a tree endemic to Tamaulipas, Mexico, distributed in the forests of the Sierra Madre Oriental. Objective: Our objective was to analyze the secondary metabolite profile of different parts of M. alejandrae and evaluate their antiproliferative activity in vitro. Methods: Different extracts of leaf, bark, and fruit were obtained using conventional and unconventional extraction methods with solvents of different polarity. The extracts were analyzed by Ultra-Performance Liquid Chromatography-Mass Spectra (UPLC-MS), and their antiproliferative activity against cancer cell lines was determined. Results: The primary yields of the extracts obtained from M. alejandrae ranged from 8.32% to 36.19%. Three hundred and twelve secondary metabolites previously reported from the Magnolia genus were detected. The most frequent were magnone A, pinoresinol, and yangambin. Honokiol and magnolol were not detected. Two of the extracts (FSW and BSW) had antiproliferative activity (IC₅₀ < 140 µg/mL) against HeLa, MCF-7, A549, U373, and PC3 cancer cell lines. The higher activity was against the A549 cell line. Conclusions: M. alejandre extracts showed secondary metabolites previously reported and unreported in other species. Interestingly, some extracts had antiproliferative activity against cancer cell lines. Therefore, M. alejandrae is a source of molecules that could be explored to develop new drugs. Full article

We quantified monthly changes in land surface temperature (LST) over the Sierra Madre Occidental (SMO) in Mexico from 2000 to 2024 using MODIS satellite imagery (MOD11B3). The SMO is the longest continuous mountain complex in Mexico, covering an area of 251,648 km². It is an area of great importance for biodiversity conservation, as it is home to numerous endemic flora and fauna species. The Intergovernmental Panel on Climate Change (IPCC) has stated that high mountain areas are among the regions most affected by climate change and are a key element of the water cycle. We calculated an anomaly index by vegetation type in the SMO and applied change detection to spatially identify where changes in LST had taken place. The lowest LST values were in December and January (20 to 25 °C), and the highest LST values occurred in April, May, and June (>40 °C). Change detection applied to the time series showed that the months with the highest positive LST changes were May to July, and that November was notable for increases of up to 5.86 °C. The time series that showed the greatest changes compared to 2000 was the series for 2024, where LST increases were found in all months of the year. The maximun average increase was 6.98 °C from 2000 to June 2005. In general, LST anomalies show a pattern of occurrence in the months of March through July for the three vegetation types distributed in the Sierra Madre Occidental. In the case of the pine forest, which is distributed at 2000 m above sea level, and higher, it was expected that there would be no LST anomalies; however, anomalies were present in all time series for the spring and early summer months. The LST values were validated with in situ data from weather stations using linear regression models. It was found that almost all the values were related, with R² > 0.60 (p < 0.001). In conclusion, the constant increases in LST throughout the SMO are probably related to the loss of 34% of forest cover due to forest fires, logging, land use changes, and increased forest plantations. Full article

Background: About half of all Major Depressive Disorder (MDD) patients have anxiety disorder. There is a neurologic basis for the comorbidity of balance (vestibular) disorders and anxiety. To detect comorbid anxiety disorder in MDD patients and, importantly, to investigate its relationship with depressive severity, we use Electrovestibulography (EVestG), which is predominantly a measure of vestibular response. Methods: In a population of 42 (26 with anxiety disorder) MDD patients, EVestG signals were measured. Fourteen (eight with anxiety disorder) were not on any anti-depressants, anti-psychotics or mood stabilizers. Using standard questionnaires, participants were depression-wise labelled as reduced symptomatic (MADRS ≤ 19, R) or symptomatic (MADRS > 19, S) as well as with or without anxiety disorder. Analyses were conducted on the whole data set, matched (age/gender/MADRS) subsets and compared with medication free subsets. Low-frequency EVestG firing pattern modulation was measured. Results: The main differences between MDD populations with and without anxiety disorder populations, regardless of being medicated or not, were (1) the presence of an increased 10.8 Hz component in the dynamic movement phase recordings, (2) the presence of asymmetric right versus left 7.6–8.9 Hz and 12.1–13.8 Hz frequency bands in the no motion (static) phase recordings, and (3) these differences were dependent on depressive severity. Conclusions: The EVestG measures are capable of quantifying anxiety in MDD patients. These measures are functions of depressive severity and are hypothesized to be linked to Hippocampal Theta (~4–12 Hz). Full article

Water availability is a major constraint on socioeconomic development in northeastern Mexico, highlighting the need for effective water resource planning that accounts for the variability and extremes of precipitation. In this study, seasonal precipitation reconstructions were developed using tree-ring chronologies from spruce species (Picea spp.). A representative chronology for Picea mexicana Martínez was developed from two populations and spans the period 1786–2020, while a chronology for Picea martinezii T.F. Patterson was established from three populations covering 1746–2020. Both species exhibited significant positive correlations with January–May precipitation (r = 0.65 and 0.71, respectively; p < 0.01) and negative correlations with maximum temperature over the same period (r = −0.52 and −0.59, respectively). Two January–May precipitation reconstructions were produced for periods with adequate sample depth (EPS > 0.85): 1851–2020 for P. mexicana and 1821–2020 for P. martinezii. Both reconstructions revealed pronounced interannual variability, with recurrent droughts and persistently dry conditions, particularly evident in the P. mexicana series. Spatial correlation analyses indicated a historical link between reconstructed precipitation and the El Niño–Southern Oscillation (ENSO). These results highlight the value of spruce species for dendroclimatic reconstruction and their sensitivity to precipitation variability, especially as rising maximum temperatures may compromise their persistence in the Sierra Madre Oriental. Full article

Introduction: The introduction of the transdiagnostic approach in psychiatry shifts the focus from discrete diagnoses to shared symptoms across various disorders. The Transdiagnostic Global Impression—Psychopathology (TGI-P) scale is a newly developed tool designed to assess psychiatric symptoms across diagnostic boundaries. It evaluates ten core symptom domains—positive, negative, cognitive, manic, depressive, addiction, anxiety, sleep, hostility, and self-harm—regardless of specific diagnoses. Objective: This study aims to evaluate the efficacy of cariprazine across these ten transdiagnostic symptom domains. Methods: A systematic literature review and meta-analysis were conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Searches were performed on EMBASE and clinicaltrials.gov. Efficacy measures such as the Positive and Negative Syndrome Scale (PANSS), Montgomery–Åsberg Depression Rating Scale (MADRS), Young Mania Rating Scale (YMRS), Hamilton Anxiety Rating Scale (HAM-A), and Columbia-Suicide Severity Rating Scale (C-SSRS) were used to assess cariprazine’s effect on the ten transdiagnostic symptoms. Multilevel random-effects meta-analyses were conducted to evaluate the efficacy of cariprazine versus placebo in alleviating depressive and anxiety symptoms across clinical trials. Results: A total of 30 studies were included in the review. Cariprazine showed therapeutic benefits on positive, negative, manic, and depressive symptoms in specifically designed trials. Preliminary positive effects were seen on anxiety, hostility, and cognitive symptoms across disorders. However, specific trials have not been conducted for anxiety disorders or cognitive impairment. Meta-analyses demonstrated that cariprazine significantly reduces both depressive and anxiety symptoms compared to placebo. Cariprazine significantly improved sleep-related symptoms in both mania and depression trials. Suicidality was evaluated in non-suicidal populations, and no increase was observed. Addiction symptoms were part of the exclusion criteria in the RCTs, so they could not be assessed. Previous reports of cariprazine’s anti-craving and anti-abuse effects come from real-world evidence rather than RCT data. Conclusions: Cariprazine appears to be promising in addressing a broad range of symptom domains across psychiatric conditions. Full article

Droughts in the Amazon region are expected to increase in frequency and intensity, which would negatively affect the tropical forest, leading to a positive climate–forest feedback loop that could potentially result in the collapse of this ecosystem. In this study, extreme drought conditions were identified in the Peruvian Amazon region for the period 2000–2024 using the maximum cumulative water deficit (MCWD) index, which is related to the tropical forest water stress. The ERA5, CHIRPS, and MSWEP datasets were used to estimate precipitation, while ERA5 data were used for evapotranspiration. This study focuses on the specificities of droughts and the differences across study areas. Six study areas were specified, three of them located in the Loreto department (northern Peruvian Amazon), another centered in Moyobamba city (western Peruvian Amazon), another in Ucayali, in the central Peruvian Amazon, and the other in Madre de Dios (southern Peruvian Amazon). It was found that the drought events are more frequent and intense in the central and southern regions of the basin. Based on the combined effect of the regional severity of the drought and its spatial extent, estimated from averaging across study areas and precipitation datasets, we identified the hydrological years of 2023-24, 2022-23, 2009-10, and 2004-05 as extreme droughts and 2015-16 and 2006-07 as moderate droughts. Full article

Background/Objectives: Transcranial Direct Current Stimulation (tDCS) has proven to be a promising intervention for major depressive disorder (MDD). Even so, the specific neurophysiological mechanisms underlying its therapeutic effects, particularly regarding frontal EEG markers, remain insufficiently understood. This pilot study investigated both the clinical efficacy and neurophysiological impact of frontal tDCS in individuals with mild to severe depression, with particular focus on mood changes and alterations in Frontal Alpha Asymmetry (FAA), Beta Symmetry, and Theta/Alpha Ratios at the F3 and F4 electrode sites. Methods: A total of thirty–one participants were enrolled and completed a standardized Flow Neuroscience tDCS protocol targeting the dorsolateral prefrontal cortex using a bilateral F3/F4 montage. The intervention included an active phase of five stimulations per week for three weeks, followed by a Strengthening Phase with two stimulations per week. Clinical outcomes were assessed using the Montgomery–Åsberg Depression Rating Scale (MADRS), while neurophysiological changes were evaluated via standardized quantitative EEG (QEEG) recordings obtained before and after the treatment course. Among the participants, fourteen individuals had a baseline MADRS score of ≥20, indicating moderate to severe depressive symptoms. Results: Following tDCS treatment, significant reductions in MADRS scores were observed across the cohort, with clinical response rates notably higher in the moderate/severe group (71.4%) compared to the mild depression group (20.0%). Neurophysiological effects were modest: no significant changes were detected in FAA or Beta Symmetry measures. However, a substantial reduction in the Theta/Alpha Ratio at F4 was found in participants with moderate to severe depression (p = 0.018, Cohen’s d = −0.72), suggesting enhanced frontal cortical activation associated with clinical improvement. Conclusions: These findings indicate that frontal tDCS is effective in reducing depressive symptoms, particularly in cases of moderate to severe depression. While improvements in FAA and Beta Symmetry were not significant, changes in the Theta/Alpha Ratio at F4 point toward dynamic neurophysiological reorganization potentially linked to therapeutic outcomes. The Theta/Alpha Ratio may serve as a promising biomarker for tracking tDCS response, whereas other EEG metrics might represent more stable trait characteristics. Future research should prioritize individualized stimulation protocols and incorporate more sensitive neurophysiological assessments, including functional connectivity analyses and task-evoked EEG paradigms, to understand the mechanisms underlying clinical improvements. Full article

Background: Transcranial photobiomodulation (t-PBM) is a promising non-invasive therapy for Major Depressive Disorder (MDD). MDD is associated with altered brain metabolism, including changes in N-acetylaspartate (NAA), choline (Cho), and creatine (Cr). This study assessed the effects of varying t-PBM doses on neurometabolite levels in the dorsolateral prefrontal cortex (dlPFC) and their correlations with clinical outcomes. Methods: In this randomized, sham-controlled, cross-over study, 33 adults with MDD received one session of t-PBM at low, medium, and high doses and a sham treatment. Proton magnetic resonance spectroscopy (1H-MRS) measured NAA, Cho, and Cr pre- and post-treatment. Clinical outcomes were assessed using the Montgomery–Åsberg Depression Rating Scale (MADRS) and the Symptoms of Depression Questionnaire (SDQ). Statistical analyses included paired t-tests or Wilcoxon signed-rank tests for neurometabolite changes, and linear mixed-effects regression models for t-PBM dose, neurometabolites, and time effects. Results: NAA levels increased significantly (7.52 ± 0.777 to 8.12 ± 1.05 mmol/L for one session; 7.36 ± 0.85 to 7.85 ± 0.68 mmol/L across all sessions); however, these changes were not associated with specific t-PBM doses or sham. No significant changes were observed for Cho and Cr levels. Positive correlations were found between Cho levels and MADRS scores (r = 0.59, p = 0.017), and negative correlations between Cr levels and SDQ scores at the medium dose (r = −0.91, p = 0.011). Conclusions: While NAA levels increased, and correlations between neurometabolites and clinical outcomes were observed, these findings do not suggest a specific effect of t-PBM. Larger randomized controlled trials with optimized dosing protocols, extended follow-up, and advanced spectroscopy are needed to clarify the neurometabolic therapeutic potential of t-PBM in MDD. Full article

Background and Objectives: Alzheimer’s disease (AD) is a progressive neurodegenerative condition that significantly affects cognitive, emotional, and functional abilities in older adults. This study aimed to explore how demographic, clinical, and psychological factors influence the progression of cognitive decline in patients diagnosed with AD. Materials and Methods: A total of 101 patients were evaluated retrospectively and followed longitudinally at three different time points, using standardized instruments, including the MMSE, Reisberg’s GDS, clock-drawing test, MADRS, and Hamilton depression scale. Statistical methods included non-parametric tests, mixed-effect modeling, and Bayesian analysis. Results: Most patients were older women from rural areas, predominantly in moderate-to-severe stages of AD. Age showed a significant association with cognitive decline (p < 0.05), and depression—particularly in moderate and severe forms—was strongly linked to lower MMSE scores (p < 0.001). Over 70% of the participants had some degree of depression. The clock-drawing test highlighted visuospatial impairments, consistent with everyday functional loss. Although donepezil and memantine combinations appeared to be more frequently prescribed, no treatment showed a statistically significant advantage, and confidence interval overlaps suggest caution in interpreting differences between therapies. Longitudinal models confirmed a progressive and accelerated decline, with inter-individual variability becoming more pronounced in later stages. Although comorbidities, such as hypertension and diabetes, were frequent, they did not show a statistically significant effect on MMSE scores in this cohort. Conclusions: Age and depression appear to play central roles in the pace of cognitive deterioration in AD. Given the limited efficacy of most current therapies, these findings highlight the need for earlier intervention and a more personalized, integrated approach—combining cognitive care, psychiatric support, and comorbidity management—to better meet the needs of patients with AD. Full article

The Sierra Madre Occidental (SMO) is a biogeographic province of Mexico that serves as a corridor for the northward expansion of subtropical species, while also acting as a barrier for the movement of species between western and eastern Mexico. The SMO houses 57 species of amphibians and 160 species of reptiles, representing 19.4% of the total number of amphibian and reptile species found in Mexico. Ten amphibian and thirteen reptile species are endemic to the SMO, and >50% of amphibian and reptile species found in the SMO are endemic to Mexico. Five amphibian species and three reptile species are listed in a category of conservation concern in the IUCN Red List. Specific threats include habitat loss, logging, mining, pollution, and climate change. The SMO shares a significant percentage of its species with neighboring provinces. In the cluster analysis for amphibians, a group comprising the SMO, the Pacific Lowlands, and the Chihuahuan Desert is linked to the Transvolcanic Belt. For reptiles, two distinct groups emerge: one including the SMO and the Chihuahuan Desert and one including the Transvolcanic Belt and the Pacific Lowlands. In conclusion, the rich biodiversity of the SMO, along with its role as both a corridor and barrier for species distribution, highlights the importance of targeted conservation efforts to mitigate the various threats facing this biogeographically significant province. Full article

Aims: This pilot study assessed the potential psychosocial and therapeutic impacts of augmenting transcranial direct current stimulation (tDCS) with cognitive behavioral therapy (CBT) in treatment-naïve patients diagnosed with major depressive disorder (MDD). Methods: In this double-blind randomized controlled trial, 10 subjects were randomized into two groups—CBT with active tDCS (active tDCS; n = 6; M = 33.3 years; 4 females) or CBT with sham tDCS (Sham; n = 4; M = 31.2 years; 2 females). Severity of depression was measured with the Montgomery–Åsberg Depression Rating Scale (MADRS) and the Beck Depression Inventory (BDI). Participants’ secondary outcomes included life satisfaction, sleep quality, and anxiety symptoms. They were assessed at baseline, following treatment (week 6), and at 2, 4, 8, and 12-week follow-ups. Results: By week 12, the active tDCS group’s BDI scores showed greater improvement relative to the sham group. There were also significant differences between groups over time in MADRS scores. Sleep quality also improved in the active tDCS group, with many participants achieving symptom-free status—defined as BDI scores of 9 or less and supported by consistently low MADRS scores—by the end of the follow-up period. Conclusions: These preliminary data indicate that the combination of tDCS with CBT may optimize the treatment of MDD through depressive symptom relief and improved sleep, while also prolonging the benefits of treatment. Full article

Background and Objectives: Transcranial alternating current stimulation (tACS) at 40 Hz has shown potential to enhance cognitive function. However, research on its combination with cognitive exercises, particularly its long-term effects in a dementia population, remains limited. This study investigated the effects of 40 Hz tACS paired with simultaneous cognitive exercises on cognition, neuropsychiatric symptoms, and the depression status of individuals with dementia in a sham-controlled, double-blind crossover design. Materials and Methods: A total of 42 participants with dementia were randomized into two groups: (1) the R1S2 group received 40 Hz real tACS with cognitive exercises, followed by a ≥8-week washout period, and then sham tACS with cognitive exercises; (2) the S1R2 group received the reversed sequence. tACS was applied at 1.5 mA peak-to-peak with electrodes over the left dorsolateral prefrontal cortex and contralateral supraorbital area. Participants received two 30 min stimulation sessions per day, 5 days per week, for 4 consecutive weeks, paired with cognitive exercises using the MindTriggers app (2.9.1). The primary outcome was the Alzheimer’s Disease Assessment Scale–Cognitive Subscale (ADAS-Cog) and the secondary outcomes included the Montgomery–Åsberg Depression Rating Scale (MADRS) and the Neuropsychiatric Inventory Questionnaire (NPI-Q). All outcome measures were assessed before and after each treatment block. Results: Real tACS paired with cognitive exercises significantly improved ADAS-Cog scores post-treatment compared to pre-treatment (p-value = 0.019), whereas sham tACS did not. Furthermore, real tACS produced significant long-term improvements approximately 2–3 months post-treatment in ADAS-Cog scores compared to sham (p-value = 0.048). Both real (p-value = 0.003) and sham (p-value = 0.015) tACS significantly reduced NPI-Q scores post-treatment. MADRS scores significantly improved (p-value = 0.007) post-treatment for real tACS but not sham. Conclusions: The 40 Hz tACS paired with cognitive exercises improves cognition, neuropsychiatric symptoms, and depression post-treatment in dementia, with sustained cognitive effects. The findings highlight its potential as a non-invasive therapeutic intervention for dementia. Full article

Geothermally heated ecosystems experience extreme temperatures and play important ecological, cultural, and socio-economic roles in many environments. They support a diversity of plants that are often used by local communities. This study focused on five hot springs with varying geochemical traits in the northeast of Mexico. The diversity surrounding each hot spring was analyzed along with the impact of climatic factors. In total, we observed 2022 individual plants across 155 species and 55 families. Shrub strata dominated the rosetophyll scrub and low thorn forest, while tree strata were more common in the tropical dry forest; the herbaceous stratum exhibited the least diversity across all sites. A decrease in species richness was observed at higher elevations, while species abundance showed an inverse trend, being highest in the rosetophyll scrub. The plant communities exhibited clear differentiation in species composition with 30 indicator species identified across the five hot springs. Notably, only Helietta parvifolia was found in three sites. The variation in plant abundance was linked to elevation and evaporation. Each type of vegetation surrounding the hot springs demonstrates unique characteristics based on plant composition, suggesting that plant diversity may offer significant benefits to the surrounding communities in the northeast of Mexico. Full article