Life Sciences Commons^™

Genetic Evaluation Of The Current Distribution And Possible Diffrentations Between Lasiurus Borealis And Lasiurus Frantzii In Southwestern North America, Zeinab M. Haidar

Cal Poly Humboldt theses and projects

Several recent accounts of overlap and historic misidentifications regarding two species of the genus Lasiurus, Western red bat (Lasiurus frantzii) and Eastern red bat (Lasiurus borealis), have cast doubt on our understanding of their distribution, assumed spatial allopatry, and interactions in the United States Southwest. With the use of morphometrics and genetic sequencing, utilizing tissue collected from specimens throughout California and adjoining states, we have reassessed the current distribution, best practices for field identification, and genetic differentiation between both species. Appropriate species classification by region was achieved utilizing mitochondrial DNA, targeting the cytochrome c oxidase …

Keep Working Hands On Working Land, Elyse Caiazzo

Graduate Student Portfolios, Professional Papers, and Capstone Projects

Strategies for Effective Farmland Transitions, Succession Planning, and Landowner Education

Investigating The Effectiveness Of Microplastic Removal And The Relationship Between Microplastics, Bacterial Communities, And Nitrogen Cycling In The Natural Treatment Systems At The Arcata Wastewater Treatment Facility, Fiona Connor

Cal Poly Humboldt theses and projects

This thesis addressed two challenging aspects of microplastic research, including the quantification of microplastics in organic-rich water, and the investigation of how microplastics impact microorganisms and related nutrient-cycling. Two projects were designed and executed to address specific research objectives relating to these broad topics. The first objective was to develop and implement methods to determine the effectiveness of microplastic removal across the natural treatment systems at the Arcata Wastewater Treatment Facility (AWTF). The second objective was to observe how microplastics found in domestic wastewater impact the bacterial communities and nitrogen cycling in freshwater treatment wetland sediment through a bench-scale experiment, …

Effect Of In Situ Experimental Heating Of Artificial Mytilus Californianus Beds On Associated Invertebrate Communities In Northern California, Claire C. Windecker

Cal Poly Humboldt theses and projects

With the continued progression of climate change, the role of foundation species as mediators of temperature stress for species living on and within them has become increasingly important. In the intertidal zone, a major foundation species is the California mussel, Mytilus californianus, which can help to limit thermal stress for species that live among aggregations of these mussels. The ability of mussels to limit thermal stress as temperatures increase, however, is still unclear. This study sought to experimentally manipulate surface temperatures of artificial mussel beds in situ to examine the effects that increased surface heating at a single site …

Neural Crest Cell Migration And Developmental Origin Of Bony Scutes In White Sturgeon (Acipenser Transmontanus), Melody Tew

Cal Poly Humboldt theses and projects

Neural crest cells (NCCs) and mesodermal somites independently produce embryonic mesenchyme as a precursor to the chondrocytes and osteocytes of the vertebrate skeleton. In mammals and teleosts, NCCs only contribute to the dermal cranial skeleton, while the mesodermal somites and lateral plate mesoderm form the entire dermal and endochondral postcranial skeleton. In sharks, NCCs contribute to both the cranial and trunk integumentary skeleton. This suggests that contribution of the trunk neural crest mesenchyme to the integumentary skeleton was an ancestral condition for all vertebrates that was lost over evolutionary time in the osteichthyan lineage, but the evolutionary timing of this …

Comparing Mexican Spotted Owl Habitat Suitability In Two Different Habitat Types Using A Multi-Scale Ensemble Learning Framework, Danial Nayeri

Cal Poly Humboldt theses and projects

Habitat fragmentation and loss are major threats to species conservation worldwide. Studying species-habitat relationships is a crucial first step toward understanding species habitat requirements, which is necessary for conservation and management planning. However, some species inhabit a range of habitat types, potentially making the use of range-wide habitat models inappropriate due to non-stationarity. The Mexican spotted owl (Strix occidentalis lucida) (MSO) is a species that inhabits both forests and rocky canyonlands, two habitats with large differences in environmental conditions. It is unclear whether the species uses habitat differently in these two habitat types or if previously builthabitat models …

Investigating Tribal Co-Management Of Caifornia’S Public Lands, Zachary Joseph Erickson

Cal Poly Humboldt theses and projects

Collaborative management with Indigenous groups is becoming increasingly common as many Indigenous communities continue to assert their inherent rights to self-determination. Due to the removal from and dispossession of lands, tribes often rely on access to public properties for various uses including ceremonies and gathering of culturally important plants. Some believe that the absence of indigenous involvement has also led to a decline in both the quality and abundance of culturally important resources, as well as limited the intergenerational transfer of traditional ecological knowledge, or TEK. There is increasing momentum toward re-engaging tribes as stewards of their ancestral lands through …

Negative Social Media And Its Influence On Athlete's Performance, Bernd R. Huber

Cal Poly Humboldt theses and projects

This study aimed to investigate the potential impact of negative social media content on athletes' cortisol levels and subsequent performance. The study focused on the change in cortisol levels and differences in free throw performance, based on previous research findings. We hypothesized that negative social media postings would increase the stress experienced by student-athletes, resulting in elevated cortisol levels and decreased performance. Additionally, participants (n = 8) completed a questionnaire to examine the interaction between preexisting fear and the biological stress response. Contrary to expectations, there was no significant change in stress response, and negative postings did not have …

Sympatric Carnivores And Vegetation Structure Influence The Distribution And Abundance Of Humboldt Martens In Northern California, Erika L. Anderson

Cal Poly Humboldt theses and projects

The Humboldt marten (Martes caurina humboldtensis) is a species facing conservation concern in Oregon and California. Historical populations were subjected to unregulated fur trapping and timber harvest throughout the late 19^th and early 20^th centuries leading to a 90% decline in their distribution. As such, the Humboldt marten is listed as a state endangered species in California, and the analogous ‘coastal marten’ is listed as federally threatened under the Endangered Species Act and classified as a Species of Greatest Conservation Need in Oregon and California. Contemporary populations are small, and isolated, and threatened by habitat loss …

A Return To The Staging Grounds: Reassessment Of Aleutian Cackling Goose Spring Distribution In North Humboldt Bay, Shaun W. Thornton

Cal Poly Humboldt theses and projects

After a 15-year interval in research, spatial and temporal patterns of the Aleutian cackling goose during spring staging was assessed again in 2022. During my study, 3,389 goose flocks were recorded in Arcata Bottoms staging site, 1 January to 21 April 2022, amounting to an estimated total of 2,248,512 goosedays, which was 336.8% higher than 2007 estimates of 667,485 goosedays. Geese continued to use pastures with a wide range of landscape characteristics primarily represented by livestock grazing practices. Goose use was greater than availability on beef-cattle fields early in the season and dairy-cow fields later in the season. Human disturbances …

Rapidly Changing Range Limits In A Warming World: Critical Data Limitations And Knowledge Gaps For Advancing Understanding Of Mangrove Range Dynamics In The Southeastern Usa, Rémi Bardou, Michael J. Osland, Steven Scyphers, Christine Shepard, Karen E. Aerni, Jahson B. Alemu I, Robert Crimian, Richard H. Day, Nicholas M. Enwright, Laura C. Feher, Sarah L. Gibbs, Kiera O'Donnell, Savannah H. Swinea, Kalaina Thorne, Sarit Truskey, Anna R. Armitage, Ronald Baker, Josh L. Breithaupt, Kyle C. Cavanaugh, Erik S. Yando, A. Randall Hughes, Et Al.

Biological Sciences Faculty Publications

Climate change is altering species’ range limits and transforming ecosystems. For example, warming temperatures are leading to the range expansion of tropical, cold-sensitive species at the expense of their cold-tolerant counterparts. In some temperate and subtropical coastal wetlands, warming winters are enabling mangrove forest encroachment into salt marsh, which is a major regime shift that has significant ecological and societal ramifications. Here, we synthesized existing data and expert knowledge to assess the distribution of mangroves near rapidly changing range limits in the southeastern USA. We used expert elicitation to identify data limitations and highlight knowledge gaps for advancing understanding of …

Corrigendum: Characterization Of A Novel Transitional Group Rickettsia Species (Rickettsia Tillamookensis Sp. Nov.) From The Western Black-Legged Tick, Ixodes Pacificus, David T. Gauthier, Sandor E. Karpathy, Stephanie L. Grizzard, Dhwani Batra, Lori A. Rowe, Christopher D. Paddock

Biological Sciences Faculty Publications

No abstract provided.

The Coral Bleaching Automated Stress System (Cbass): A Low Cost, Portable System For Standardized Empirical Assessments Of Coral Thermal Limits, Nicolas R. Evensen, Katherine E. Parker, Thomas A. Oliver, Stephen R. Palumbi, Cheryl A. Logan, James S. Ryan, Courtney N. Klepac, Gabriela Perna, Mark E. Warner, Christian R. Voolstra, Daniel J. Barshis

Biological Sciences Faculty Publications

Ocean warming is increasingly affecting marine ecosystems across the globe. Reef-building corals are particularly affected by warming, with mass bleaching events increasing in frequency and leading to widespread coral mortality. Yet, some corals can resist or recover from bleaching better than others. Such variability in thermal resilience could be critical to reef persistence; however, the scientific community lacks standardized diagnostic approaches to rapidly and comparatively assess coral thermal vulnerability prior to bleaching events. We present the Coral Bleaching Automated Stress System (CBASS) as a low-cost, open-source, field-portable experimental system for rapid empirical assessment of coral thermal thresholds using standardized temperature …

Fine-Scale Genetic Structure In Rhizosphere Microbial Communities Associated With Chamaecrista Fasciculata (Fabaceae), Mahboubeh Hosseinalizadeh Nobarinezhad, Lisa E. Wallace

Biological Sciences Faculty Publications

Soil microbiota of the rhizosphere are an important extension of the plant phenotype because they impact the health and fitness of host plants. The composition of these communities is expected to differ among host plants due to influence by host genotype. Given that many plant populations exhibit fine-scale genetic structure (SGS), associated microbial communities may also exhibit SGS. In this study, we tested this hypothesis using Chamaecrista fasciculata, a legume species that has previously been determined to have significant SGS. We collected genetic data from prokaryotic and fungal rhizosphere communities in association with 70 plants in an area of …

Co-Occurrence Of Marine And Freshwater Phycotoxins In Oysters, And Analysis Of Possible Predictors For Management, Sarah K. D. Pease, Todd A. Egerton, Kimberly S. Reece, Marta P. Sanderson, Michelle D. Onofrio, Evan Yeargan, Adam Wood, Amanda Roach, I-Shuo Wade Huang, Gail P. Scott, Allen R. Place, Amy M. Hayes, Juliette L. Smith

Biological Sciences Faculty Publications

Oysters (Crassostrea virginica) were screened for 12 phycotoxins over two years in nearshore waters to collect baseline phycotoxin data and to determine prevalence of phycotoxin co-occurrence in the commercially and ecologically-relevant species. Trace to low concentrations of azaspiracid-1 and -2 (AZA1, AZA2), domoic acid (DA), okadaic acid (OA), and dinophysistoxin-1 (DTX1) were detected, orders of magnitude below seafood safety action levels. Microcystins (MCs), MC-RR and MC-YR, were also found in oysters (maximum: 7.12 μg MC-RR/kg shellfish meat wet weight), warranting consideration of developing action levels for freshwater phycotoxins in marine shellfish. Oysters contained phycotoxins that impair shellfish health: karlotoxin1-1 and …

A Multi-Isotope Approach Reveals Seasonal Variation In The Reliance On Marine Resources, Production Of Metabolic Water, And Ingestion Of Seawater By Two Species Of Coastal Passerine To Maintain Water Balance, Lucas Navarrete, Nico Lübcker, Felipe Alvarez, Roberto Nespolo, Juan Carlos Sanchez-Hernandez, Karin Maldonado, Zachary D. Sharp, John P. Whiteman, Seth D. Newsome, Pablo Sabat

Biological Sciences Faculty Publications

Tracing how free-ranging organisms interact with their environment to maintain water balance is a difficult topic to study for logistical and methodological reasons. We use a novel combination of triple-oxygen stable isotope analyses of water extracted from plasma (δ¹⁶O, δ¹⁷O, δ¹⁸O) and bulk tissue carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes of feathers and blood to estimate the proportional contribution of marine resources, seawater, and metabolic water used by two species of unique songbirds (genus Cinclodes) to maintain their water balance in a seasonal coastal environment. We …

The Practice And Promise Of Temporal Genomics For Measuring Evolutionary Responses To Global Change, René D. Clark, Katrina A. Catalano, Kyra S. Fitz, Eric Garcia, Kyle E. Jaynes, Brendan N. Reid, Allyson Sawkins, Anthony A. Snead, John C. Whalen, Malin L. Pinsky

Biological Sciences Faculty Publications

Understanding the evolutionary consequences of anthropogenic change is imperative for estimating long-term species resilience. While contemporary genomic data can provide us with important insights into recent demographic histories, investigating past change using present genomic data alone has limitations. In comparison, temporal genomics studies, defined herein as those that incorporate time series genomic data, utilize museum collections and repeated field sampling to directly examine evolutionary change. As temporal genomics is applied to more systems, species and questions, best practices can be helpful guides to make the most efficient use of limited resources. Here, we conduct a systematic literature review to synthesize …

Disparate Population And Holobiont Structure Of Pocilloporid Corals Across The Red Sea Gradient Demonstrate Species-Specific Evolutionary Trajectories, Carol Buitrago-López, Anny Cárdenas, Benjamin C.C. Hume, Thierry Gosselin, Fabian Staubach, Manuel Aranda, Daniel J. Barshis, Yvonne Sawall, Christian R. Voolstra

Biological Sciences Faculty Publications

Global habitat degradation heightens the need to better understand patterns of genetic connectivity and diversity of marine biota across geographical ranges to guide conservation efforts. Corals across the Red Sea are subject to pronounced environmental differences, but studies so far suggest that animal populations are largely connected, excepting evidence for a genetic break between the northern-central and southern regions. Here, we investigated population structure and holobiont assemblage of two common pocilloporid corals, Pocillopora verrucosa and Stylophora pistillata, across the Red Sea. We found little evidence for population differentiation in P. verrucosa, except for the southernmost site. Conversely, S. …

Nilgai, Boselaphus Tragocamelus And White-Tailed Deer, Odocoileus Virginianus Use Of Water Troughs With And Without Remotely Operated Field Sprayers For Potential Treatment Of Cattle Fever Ticks, John A. Goolsby, Mauricio Cruz, Reyes Garcia Iii, Lauren P. Maestas, Teresa Patricia Feria-Arroyo

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Nilgai antelope, Boselaphus tragocamelus and white-tailed deer (WTD), Odocoileus virginianus are hosts of cattle fever ticks, Rhipicephalus (=Boophilus) microplus, in the Lower Rio Grande Valley of South Texas. Daily use of water troughs and ponds were observed to determine if these locations could be used for field treatment methods for cattle fever ticks using remotely operated field sprayers. Game cameras (n=16) were deployed between June 2020 and September 2022 at two private ranches in Cameron County, TX. Both nilgai and WTD visited water troughs equipped with motion detecting sprayers in similar numbers to ponds, but numbers of animal visits were …

Intra- And Inter-Rater Reliability Of Maximum Torque Applied During Passive Elbow Range Of Motion Testing Post-Casting Of Supracondylar And Lateral Condylar Fractures In Children, Joseph T. Armstrong

Theses and Dissertations--Kinesiology and Health Promotion

Elbow fractures account for a significant number of pediatric orthopedic injuries. The most common of these are the supracondylar and lateral condylar humeral fractures. When surgical repair is necessary casting and pinning of the elbow can affect the elbow’s range of motion (ROM), so recovery is monitored. Practices for measuring recovery are not standardized so measures may not be consistent. A possible novel measure to help account for different clinicians participating in the same study is maximum torque applied during elbow end ROM testing. This study uses several comparisons of maximum torque applied by three different clinicians during end ROM …

Effects Of Constant Load Exercise On Oxygen Consumption And Knee Joint Mechanics In Young Adults, Mariana Victoria Jacobs

Theses and Dissertations--Kinesiology and Health Promotion

The rate of obesity and its adverse health consequences have continued to rise in the past several decades. Aerobic constant load exercise is recommended to reduce excess body mass, however the effects of constant load exercise on oxygen consumption (VO2) and knee joint mechanics are inconsistent when varying weight-status strategies are employed. The purpose of this study was to assess the influence of different weight classification strategies on VO2 and knee joint mechanics during constant load exercise. Participants walked on an instrumented treadmill at a self-selected speed for 30-minutes while gait mechanics and VO2 measures were determined. Between-group differences were …

Responses To Exercise Anchored To Vigorous Intensity Heart Rates, Djadmann Gustave

Theses and Dissertations--Kinesiology and Health Promotion

Exercise prescription to improve cardiorespiratory endurance (CE) is often based on percentages of the reserve or maximum heart rate (HR_peak) or oxygen consumption rate (V̇O_2peak)that reflect vigorous intensities (77-95% HR_peak, 64-90% V̇O_2peak). These intensities elicit a rating of perceived exertion [RPE] response between 14-17 on the 6-20 Borg Scale. It is recommended that exercise within these ranges be sustained for 20-60min per session. The purposes of this study were to: 1) Determine the metabolic (V̇O₂) and perceptual (RPE) responses as well as the sustainability of exercise (time to exhaustion [T …

Effect Of Sleep Restriction On Quadriceps’ Strength And Voluntary Activation, Scott Sigrist

Theses and Dissertations--Kinesiology and Health Promotion

Background: As little as three nights of sleep restriction reduces muscle strength. More than one-third of Americans are chronically sleep restricted (< 7.0 hours/night) and are at risk of muscle weakness (dynapenia). Presently, the mechanistic cause of sleep restriction-induced dynapenia (SRID) has not been elucidated. Rapid changes in muscle strength are typically driven by short-term changes in muscle contractility or voluntary recruitment. The purpose of this study was to investigate how sleep restriction affects muscle contractile function and voluntary recruitment. Methods: A sample of 12 subjects (age 24.8 ± 2.6y) underwent isometric and isokinetic knee extensor muscle testing following 3d of adequate sleep (SA; 8.05 ± 0.45h), 3 d of sleep restriction (SR; 5.02 ± 0.05h), and 7d of washout (WO, 8.27 ± 0.50). The morning (7-11a local time) following the last day of each sleep period, subjects performed muscle strength testing using an isokinetic dynamometer. Subjects sat upright with the dominant leg secured at 60⁰ of knee flexion to optimize maximal quadriceps torque. They then performed 3 maximal voluntary isometric contractions (MVICs) of the quadriceps. Then subjects performed 6 submaximal contractions at 15, 30, 45, 60, 75, and 90% of the greatest MVIC. Next, subjects completed an interpolated twitch experiment while on the isokinetic dynamometer to assess voluntary activation. Finally, subjects completed 5 repetitions of isometric contractions, in descending order, at speeds of 300, 240, 180, 120, and 60 degree/s. From these methods we measured the highest MVIC, calculated the voluntary activation (VA), measured twitch properties, and compared the torque-EMG relationship. One-way repeated measures ANOVA were used to compare sleep, MVIC, and VA values, two-way (time x twitch property) repeated measures ANOVA was used to compare twitch properties and the torque-EMG relationship. Results: MVIC torque decreased following SR compared to SA before and after sleep restriction (SA: 217.1 ± 69.4 Nm vs. SR: 199.4 ± 67.1 Nm, p = 0.032). MVIC after WO (219.2 ± 54.2 Nm) was significantly greater than SR (p = 0.018) but was not significantly different from SA (p = 0.991). Although peak isokinetic torque decreased with increasing velocity (p < 0.001), there was no significant effect of sleep or sleep x speed interaction. Peak twitch torque and rate of torque
development, but not relaxation rate, were significantly greater in the potentiated state, but no significant effect of sleep or sleep x time interaction was noted. Sleep 3 condition did not significantly affect voluntary activation (SA: 86.3 ± 11.1% v. SR:86.6 ± 11.9% v. WO 87.7 ± 11.1%; p = 0.695). The torque output at various levels ofelectromyography (EMG) activity was not significantly different among sleep conditions (p = 0.383). The mean power frequency (MPF) of the VL was …

Investigation Of Lower Extremity Neuromuscular Function In Individuals With And Without Diabetes, Roya Hoveizavi

Theses and Dissertations--Kinesiology and Health Promotion

Background: Diabetes mellitus is associated with notable neuromuscular and motor dysfunctions that could lead to an increased risk of plantar ulcers and amputations. Several contributing factors, including increased muscle-tendon stiffness and abnormal muscle activation pattern may influence the kinematics and kinetics of walking in people with diabetes and promote formation of plantar ulcers. Hyperglycemia and the resultant accelerated rate of glycation have been recognized as the leading cause of muscle and tendon degeneration, yet the precise mechanisms by which diabetes affects the biomechanical properties of the muscle-tendon unit remains unclear. Altered muscle activity during gait is observed in people with …

The Effect Of Physical Activity Courses On The Motivation For Physical Activity In College Students: A Scoping Review, Erica Fauste Waizenhofer Hill

Theses and Dissertations--Kinesiology and Health Promotion

The lack of physical activity and exercise participation has been an ongoing
problem for young adults aged 18-24. Universities and colleges worldwide offer a variety of required and elective physical activity courses for college credit to increase active participation in lifelong healthy lifestyles. This scoping review collected studies on college students’ motivation to participate in physical activity. The courses were taught using methods based on motivational theories. The authors of the studies collected information from the students before and after the classes to gather data on the theoretical framework’s effect on the students, if any. This review compiles this information, …

Reliability And Validity Of A Commercial Running Power Meter To Indicate Metabolic Workload During Endurance Running, James Harris Hudgins Iii

Theses and Dissertations--Kinesiology and Health Promotion

Commercial running power (RP) meters may provide endurance runners and coaches with improved precision for monitoring running intensity. Cyclists rely upon the relationship between cycling power and metabolic demand to regulate physiological intensity during training and racing, independent of changes in the physical environment (e.g., terrain, wind). Research demonstrates strong reliability and validity for a specific RP meter to indicate metabolic demand within controlled running conditions. However, several potential influences on this relationship have not been investigated. Therefore, four studies were conducted with the following aims:

- Study 1: Determine the inter-limb reliability and validity of a single-limb-based RP meter …

The Effects Of Cannabidiol Cream On Soreness And Performance After Exercise In Untrained Individuals, Joseph Thomas Pastina

Theses and Dissertations--Kinesiology and Health Promotion

Background: Exercise-induced muscle damage (EIMD) results from unaccustomed exercise and can lead to delayed onset muscle soreness (DOMS). Impairments associated with EIMD and DOMS can result in moderate-to-severe discomfort and hindered performance. Recently, a compound derived from the cannabis plant, cannabidiol (CBD), has been used as a recovery tool for EIMD and DOMS. Despite the rising popularity of CBD products, their effectiveness in mitigating EIMD and DOMS is unknown. Purpose: The purpose of the present study was to investigate the effects of CBD cream on DOMS and performance after an intensive lower-body exercise protocol. In addition, the study sought to …

The Effects Of Saddle Angle/Inclination On Lumbopelvic Kinematics And Cardiometabolic Measures, Andrew Nathan Anderson

Theses and Dissertations--Kinesiology and Health Promotion

Lower back pain (LBP) is a condition which affects the lumbar portion of the spinal column that can lead to mild to extreme physical pain during seated tasks and has been shown to be prevalent in people who spend long durations sitting particularly in a slumped position or in a position with a large degree of lumbar flexion. LBP can cause regular interruptions in work and in a person’s ability to engage in exercise, and in most extreme cases warrants surgical interventions for clinical treatment. While LBP is prevalent in sedentary populations, it is also quite prevalent in cycling populations …

The Relationship Of Multidimensional Athlete Characteristics Versus Competition Performance And Participation In American Football Players, Alex Brownell

Theses and Dissertations--Kinesiology and Health Promotion

BACKGROUND: Athlete evaluation in American football is dominated by the evaluation characteristics that underly key performance indicators (KPI’s) in the physical domain of performance. Team sport athlete performance is comprised of a combination of attributes in the physical, technical, tactical, and mental domains of performance. Using only KPI’s in the physical domain of performance to predict competition performance of American football athletes is challenging due to the differences in performance outcomes of the varying positions in American football and absence of the other performance dimensions that are not accounted for. Advances in athlete assessment have revolutionized the process of evaluating …

Assessment Of Hypothyroidism Among Adult Patients Suffering From Beta Thalassemia Major, Ahmed Saleh Ibrahim, Azza Hasan Abd El-Fatah, Ayman Fathy Abd El-Halim, Fared Fawzy Mohamed

Mansoura Medical Journal

Background: Although beta thalassemia major (BTM) patients are properly treated with blood transfusions in accompany with iron chelation therapy, they suffer from serious complications such as hypothyroidism. Aim: This work aims to assess hypothyroidism among adult with β-thalassemia major patients and to find out its association with various parameters such as age, body mass index (BMI) ,gender ,hemoglobin(Hb) and serum ferritin levels. Methods: This cross-sectional study included 200 adult BTM patients (males 115 and females 85 ; mean age 24.684 ±5.30761 years; ranging from 18 to 43 years old). Statistical data analysis was performed using IBM-SPSS software package version 26.0. …