NobleBlocks

Florida Agricultural and Mechanical University

UniversityTallahassee, United States

Research output, citation impact, and the most-cited recent papers from Florida Agricultural and Mechanical University (United States). Aggregated across the NobleBlocks index of 300M+ scholarly works.

Total works
8.7K
Citations
275.1K
h-index
169
i10-index
5.9K
Also known as
Florida A&M UniversityFlorida Agricultural and Mechanical UniversityUniversidad Agrónoma y Mecánica de Florida

Top-cited papers from Florida Agricultural and Mechanical University

Teaching Learners To Be Self-Directed
Gerald Grow
1991· Adult Education Quarterly970doi:10.1177/0001848191041003001

Based on the Situational Leadership model of Hersey and Blanchard (1988), the Staged Self-Directed Learning Model proposes that learners advance through stages of increasing self-direction and that teachers can help or hinder that development. Good teaching matches the learner's stage of self-direction and helps the learner advance toward greater self-direction. Specific methods are proposed for teaching students at each stage, although many different teaching styles are good when appropriately applied. Several pedagogical difficulties are explained as mismatches between teacher style and learner stage, especially the mismatch between a student needing direction and a non-directive teacher.

The Tree of Life and a New Classification of Bony Fishes
Ricardo Betancur‐R, Richard E. Broughton, E. O. Wiley, Kent E. Carpenter +4 more
2013· PLoS Currents846doi:10.1371/currents.tol.53ba26640df0ccaee75bb165c8c26288

The tree of life of fishes is in a state of flux because we still lack a comprehensive phylogeny that includes all major groups. The situation is most critical for a large clade of spiny-finned fishes, traditionally referred to as percomorphs, whose uncertain relationships have plagued ichthyologists for over a century. Most of what we know about the higher-level relationships among fish lineages has been based on morphology, but rapid influx of molecular studies is changing many established systematic concepts. We report a comprehensive molecular phylogeny for bony fishes that includes representatives of all major lineages. DNA sequence data for 21 molecular markers (one mitochondrial and 20 nuclear genes) were collected for 1410 bony fish taxa, plus four tetrapod species and two chondrichthyan outgroups (total 1416 terminals). Bony fish diversity is represented by 1093 genera, 369 families, and all traditionally recognized orders. The maximum likelihood tree provides unprecedented resolution and high bootstrap support for most backbone nodes, defining for the first time a global phylogeny of fishes. The general structure of the tree is in agreement with expectations from previous morphological and molecular studies, but significant new clades arise. Most interestingly, the high degree of uncertainty among percomorphs is now resolved into nine well-supported supraordinal groups. The order Perciformes, considered by many a polyphyletic taxonomic waste basket, is defined for the first time as a monophyletic group in the global phylogeny. A new classification that reflects our phylogenetic hypothesis is proposed to facilitate communication about the newly found structure of the tree of life of fishes. Finally, the molecular phylogeny is calibrated using 60 fossil constraints to produce a comprehensive time tree. The new time-calibrated phylogeny will provide the basis for and stimulate new comparative studies to better understand the evolution of the amazing diversity of fishes.

Coupling biogeochemical cycles in urban environments: ecosystem services, green solutions, and misconceptions
Diane E Pataki, Margaret M. Carreiro, Jennifer Cherrier, N. E. Grulke +4 more
2011· Frontiers in Ecology and the Environment837doi:10.1890/090220

Urban green space is purported to offset greenhouse‐gas (GHG) emissions, remove air and water pollutants, cool local climate, and improve public health. To use these services, municipalities have focused efforts on designing and implementing ecosystem‐services‐based “green infrastructure” in urban environments. In some cases the environmental benefits of this infrastructure have been well documented, but they are often unclear, unquantified, and/or outweighed by potential costs. Quantifying biogeochemical processes in urban green infrastructure can improve our understanding of urban ecosystem services and disservices (negative or unintended consequences) resulting from designed urban green spaces. Here we propose a framework to integrate biogeochemical processes into designing, implementing, and evaluating the net effectiveness of green infrastructure, and provide examples for GHG mitigation, stormwater runoff mitigation, and improvements in air quality and health.

Scientists' warning to humanity on insect extinctions
Pedro Cardoso, Philip S. Barton, Klaus Birkhofer, Filipe Chichorro +4 more
2020· Biological Conservation824doi:10.1016/j.biocon.2020.108426

Here we build on the manifesto ‘World Scientists’ Warning to Humanity, issued by the Alliance of World Scientists. As a group of conservation biologists deeply concerned about the decline of insect populations, we here review what we know about the drivers of insect extinctions, their consequences, and how extinctions can negatively impact humanity. We are causing insect extinctions by driving habitat loss, degradation, and fragmentation, use of polluting and harmful substances, the spread of invasive species, global climate change, direct overexploitation, and co-extinction of species dependent on other species. With insect extinctions, we lose much more than species. We lose abundance and biomass of insects, diversity across space and time with consequent homogenization, large parts of the tree of life, unique ecological functions and traits, and fundamental parts of extensive networks of biotic interactions. Such losses lead to the decline of key ecosystem services on which humanity depends. From pollination and decomposition, to being resources for new medicines, habitat quality indication and many others, insects provide essential and irreplaceable services. We appeal for urgent action to close key knowledge gaps and curb insect extinctions. An investment in research programs that generate local, regional and global strategies that counter this trend is essential. Solutions are available and implementable, but urgent action is needed now to match our intentions.

Observation of a Narrow Meson State Decaying to<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msubsup><mml:mi>D</mml:mi><mml:mi>s</mml:mi><mml:mo>+</mml:mo></mml:msubsup><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math>at a Mass of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mn>2.32</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi mathvariant="normal">G</mml:mi><mml:mi mathvariant="normal">e</mml:mi><mml:mi mathvariant="normal">V</mml:mi><mml:mo>/</mml:mo><mml:msup><mml:mi>c</mml:mi><mml:mn>2</mml:mn></mml:msup></mml:math>
B. Aubert, R. Barate, D. Boutigny, J.-M. Gaillard +4 more
2003· Physical Review Letters704doi:10.1103/physrevlett.90.242001

We have observed a narrow state near $2.32\text{ }\mathrm{G}\mathrm{e}\mathrm{V}/{c}^{2}$ in the inclusive ${D}_{s}^{+}{\ensuremath{\pi}}^{0}$ invariant mass distribution from ${e}^{+}{e}^{\ensuremath{-}}$ annihilation data at energies near 10.6 GeV. The observed width is consistent with the experimental resolution. The small intrinsic width and the quantum numbers of the final state indicate that the decay violates isospin conservation. The state has natural spin-parity and the low mass suggests a ${J}^{P}={0}^{+}$ assignment. The data sample corresponds to an integrated luminosity of $91\text{ }{\mathrm{f}\mathrm{b}}^{\ensuremath{-}1}$ recorded by the BABAR detector at the SLAC PEP-II asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ storage ring.

Abusive Supervision: A Meta-Analysis and Empirical Review
Jeremy D. Mackey, Rachel E. Frieder, Jeremy Ray Brees, Mark J. Martinko
2015· Journal of Management672doi:10.1177/0149206315573997

We conducted a meta-analysis and empirical review of abusive supervision research in order to derive meta-analytic population estimates for the relationships between perceptions of abusive supervision and numerous demographic, justice, individual difference, leadership, and outcome variables. The use of psychometric correction enabled us to provide weighted mean correlations and population correlation estimates that accounted for attenuation due to measurement error and sampling error variance. Also, we conducted sensitivity analyses that removed the effects of large samples from analyses. Then, we conducted subgroup analyses using samples drawn from the United States to provide population correlation estimates that corrected for attenuation due to measurement error, sampling error variance, and indirect range restriction. Finally, we examined measurement artifacts resulting from various adaptations of Tepper’s abusive supervision measure. The results reveal that although the associations between perceptions of abusive supervision and outcome variables appear to be universally negative, the magnitude of the relationships between perceptions of abusive supervision and antecedent and outcome variables varies according to the design features of studies. Contributions to theory and practice, strengths and limitations, and directions for future research are discussed.

A Review of Coumarin Derivatives in Pharmacotherapy of Breast Cancer
Musiliyu A. Musa, John S. Cooperwood, M Omar F Khan
2008· Current Medicinal Chemistry540doi:10.2174/092986708786242877

The coumarin (benzopyran-2-one, or chromen-2-one) ring system, present in natural products (such as the anticoagulant warfarin) that display interesting pharmacological properties, has intrigued chemists and medicinal chemists for decades to explore the natural coumarins or synthetic analogs for their applicability as drugs. Many molecules based on the coumarin ring system have been synthesized utilizing innovative synthetic techniques. The diversity oriented synthetic routes have led to interesting derivatives including the furanocoumarins, pyranocoumarins, and coumarin sulfamates (COUMATES), which have been found to be useful in photochemotherapy, antitumor and anti-HIV therapy, and as stimulants for central nervous system, antibacterials, anti-inflammatory, anti-coagulants, and dyes. Of particular interest in breast cancer chemotherapy, some coumarins and their active metabolite 7-hydroxycoumarin analogs have shown sulfatase and aromatase inhibitory activities. Coumarin based selective estrogen receptor modulators (SERMs) and coumarin-estrogen conjugates have also been described as potential antibreast cancer agents. Since breast cancer is the second leading cause of death in American women behind lung cancer, there is a strong impetus to identify potential new drug treatments for breast cancer. Therefore, the objective of this review is to focus on important coumarin analogs with antibreast cancer activities, highlight their mechanisms of action and structure-activity relationships on selected receptors in breast tissues, and the different methods that have been applied in the construction of these pharmacologically important coumarin analogs.

Digital twins for health: a scoping review
Evangelia Katsoulakis, Qi Wang, Huanmei Wu, Leili Shahriyari +4 more
2024· npj Digital Medicine535doi:10.1038/s41746-024-01073-0

The use of digital twins (DTs) has proliferated across various fields and industries, with a recent surge in the healthcare sector. The concept of digital twin for health (DT4H) holds great promise to revolutionize the entire healthcare system, including management and delivery, disease treatment and prevention, and health well-being maintenance, ultimately improving human life. The rapid growth of big data and continuous advancement in data science (DS) and artificial intelligence (AI) have the potential to significantly expedite DT research and development by providing scientific expertise, essential data, and robust cybertechnology infrastructure. Although various DT initiatives have been underway in the industry, government, and military, DT4H is still in its early stages. This paper presents an overview of the current applications of DTs in healthcare, examines consortium research centers and their limitations, and surveys the current landscape of emerging research and development opportunities in healthcare. We envision the emergence of a collaborative global effort among stakeholders to enhance healthcare and improve the quality of life for millions of individuals worldwide through pioneering research and development in the realm of DT technology.

Determinants of Employee Job Satisfaction: An Empirical Test of a Causal Model
Augustine O. Agho, Charles W. Mueller, James L. Price
1993· Human Relations513doi:10.1177/001872679304600806

The job satisfaction model embedded in the Price-Mueller turnover model was revised and estimated. The revised model examined the effects of a series of environmental, job characteristics, and personality variables that were excluded from the Price-Mueller model. Two-wave longitudinal data were collected from 405 employees of a 327-bed Veterans Administration Medical Center. Four different models representing refinements of the proposed model were estimated using LISREL maximum likelihood methods. The exclusion of important job characteristics (role conflict, supervisory support, and task significance) by the Price-Mueller model was not found to have a significant impact on the explanatory power of the revised model. However, the exclusion of an environmental factor (opportunity) and a personality variable (positive affectivity) was found to be a serious omission. Overall, it was found that the degree to which employees like their job is influenced by a combination of characteristics of the environment (opportunity), the job (routinization and distributive justice), and personality variables (positive affectivity and work motivation). Fifty-seven percent (57%) of the variance in job satisfaction was explained by the revised model, as compared with 49% for the Price-Mueller model.

Electrode Materials, Electrolytes, and Challenges in Nonaqueous Lithium‐Ion Capacitors
Bing Li, Junsheng Zheng, Junsheng Zheng, Hongyou Zhang +4 more
2018· Advanced Materials506doi:10.1002/adma.201705670

Among the various energy-storage systems, lithium-ion capacitors (LICs) are receiving intensive attention due to their high energy density, high power density, long lifetime, and good stability. As a hybrid of lithium-ion batteries and supercapacitors, LICs are composed of a battery-type electrode and a capacitor-type electrode and can potentially combine the advantages of the high energy density of batteries and the large power density of capacitors. Here, the working principle of LICs is discussed, and the recent advances in LIC electrode materials, particularly activated carbon and lithium titanate, as well as in electrolyte development are reviewed. The charge-storage mechanisms for intercalative pseudocapacitive behavior, battery behavior, and conventional pseudocapacitive behavior are classified and compared. Finally, the prospects and challenges associated with LICs are discussed. The overall aim is to provide deep insights into the LIC field for continuing research and development of second-generation energy-storage technologies.

Discriminant validity of measures of job satisfaction, positive affectivity and negative affectivity
Augustine O. Agho, James L. Price, Charles W. Mueller
1992· Journal of Occupational and Organizational Psychology497doi:10.1111/j.2044-8325.1992.tb00496.x

The discriminant validity of measures used to assess job satisfaction, positive affectivity and negative affectivity was empirically evaluated using data collected from a sample of 550 employees of a 327‐bed Veterans Administration Medical Center. Confirmatory factor analysis with LISREL as the estimation technique was used to test the hypothesized three‐factor configuration. Results of this test and other data supported the discriminant validity of the three constructs.

Recent Advances and Uses of Grape Flavonoids as Nutraceuticals
Vasil Georgiev, Anthony Ananga, Violeta Tsolova
2014· Nutrients485doi:10.3390/nu6010391

Grape is one of the oldest fruit crops domesticated by humans. The numerous uses of grape in making wine, beverages, jelly, and other products, has made it one of the most economically important plants worldwide. The complex phytochemistry of the berry is characterized by a wide variety of compounds, most of which have been demonstrated to have therapeutic or health promoting properties. Among them, flavonoids are the most abundant and widely studied, and have enjoyed greater attention among grape researchers in the last century. Recent studies have shown that the beneficial health effects promoted by consumption of grape and grape products are attributed to the unique mix of polyphenolic compounds. As the largest group of grape polyphenols, flavonoids are the main candidates considered to have biological properties, including but not limited to antioxidant, anti-inflammatory, anti-cancer, antimicrobial, antiviral, cardioprotective, neuroprotective, and hepatoprotective activities. Here, we discuss the recent scientific advances supporting the beneficial health qualities of grape and grape-derived products, mechanisms of their biological activity, bioavailability, and their uses as nutraceuticals. The advantages of modern plant cell based biotechnology as an alternative method for production of grape nutraceuticals and improvement of their health qualities are also discussed.

Study of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:mi>J</mml:mi><mml:mo>/</mml:mo><mml:mi>ψ</mml:mi><mml:msup><mml:mi>K</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math>decay and measurement of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:mi>X</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mn>3872</mml:mn><mml:mo stretchy="false">)</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math>branching fraction
B. Aubert, R. Barate, D. Boutigny, F. Couderc +4 more
2005· Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D, Particles, fields, gravitation, and cosmology456doi:10.1103/physrevd.71.071103

We study the decay B- --&gt; J/psi K- pi+ pi- using 117 million BBbar events collected at the Y(4S) resonance with the BaBar detector at the PEP-II e+ e- asymmetric-energy storage ring. We measure the branching fractions Br(B- --&gt; J/psi K- pi+ pi-) = (116 +- 7 (stat.) +- 9(syst.))* 10-5 and Br(B- --&gt; X(3872)K-)* Br (X(3872) --&gt; J/psi pi+ pi-) =(1.28+- 0.41)* 10-5 and find the mass of the X(3872) to be 3873.4 +- 1.4 MeV/c2. We search for the h_c narrow state in the decay B- --&gt; h_c K-, h_c --&gt; J/psi pi+ pi- and for the decay B- --&gt; J/psi D0 pi-, with D0 --&gt; K- pi+. We set the 90% C.L. limits Br(B- --&gt; h_c K-)* Br (h_c --&gt; J/psi pi+ pi-) &lt;3.4 * 10-6 and Br(B- --&gt; J/psi D0 pi-) &lt;5.2 * 10-5.

Competitive Displacement Among Insects and Arachnids
Stuart R. Reitz, John T. Trumble
2002· Annual Review of Entomology443doi:10.1146/annurev.ento.47.091201.145227

Competitive displacement is the most severe outcome of interspecific competition. For the purposes of this review, we define this type of displacement as the removal of a formerly established species from a habitat as a result of direct or indirect competitive interactions with another species. We reviewed the literature for recent putative cases of competitive displacement among insects and arachnids and assessed the evidence for the role of interspecific competition in these displacements. We found evidence for mechanisms of both exploitation and interference competition operating in these cases of competitive displacement. Many of the cases that we identified involve the operation of more than one competitive mechanism, and many cases were mediated by other noncompetitive factors. Most, but not all, of these displacements occurred between closely related species. In the majority of cases, exotic species displaced native species or previously established exotic species, often in anthropogenically-altered habitats. The cases that we identified have occurred across a broad range of taxa and environments. Therefore we suggest that competitive displacement has the potential to be a widespread phenomenon, and the frequency of these displacement events may increase, given the ever-increasing degree of anthropogenic changes to the environment. A greater awareness of competitive displacement events should lead to more studies documenting the relative importance of key factors and developing hypotheses that explain observed patterns.

The Physics of the B Factories
A. J. Bevan, B. Golob, Th. Mannel, S. Prell +4 more
2014· The European Physical Journal C427doi:10.1140/epjc/s10052-014-3026-9

(c) The Author(s) 2014. This article is published with open access at Springerlink.com.&#13;\nThis article is distributed under the terms of&#13;\nthe Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited. Funded by SCOAP3 / License Version CC BY 4.0.

Interaction of nanoparticles and cell-penetrating peptides with skin for transdermal drug delivery
Pinaki R. Desai, Ram R. Patlolla, Mandip Singh
2010· Molecular Membrane Biology403doi:10.3109/09687688.2010.522203

Topical or transdermal drug delivery is challenging because the skin acts as a natural and protective barrier. Therefore, several methods have been examined to increase the permeation of therapeutic molecules into and through the skin. One approach is to use the nanoparticulate delivery system. Starting with liposomes and other vesicular systems, several other types of nanosized drug carriers have been developed such as solid lipid nanoparticles, nanostructured lipid carriers, polymer-based nanoparticles and magnetic nanoparticles for dermatological applications. This review article discusses how different particulate systems can interact and penetrate into the skin barrier. In this review, the effectiveness of nanoparticles, as well as possible mode of actions of nanoparticles, is presented. In addition to nanoparticles, cell-penetrating peptide (CPP)-mediated drug delivery into the skin and the possible mechanism of CPP-derived delivery into the skin is discussed. Lastly, the effectiveness and possible mechanism of CPP-modified nanocarriers into the skin are addressed.

Ecological and socioeconomic impacts of invasive alien species in island ecosystems
Jamie K. Reaser, Laura A. Meyerson, Quentin Cronk, Maj De Poorter +4 more
2007· Environmental Conservation385doi:10.1017/s0376892907003815

Minimizing the impact of invasive alien species (IAS) on islands and elsewhere requires researchers to provide cogent information on the environmental and socioeconomic consequences of IAS to the public and policy makers. Unfortunately, this information has not been readily available owing to a paucity of scientific research and the failure of the scientific community to make their findings readily available to decision makers. This review explores the vulnerability of islands to biological invasion, reports on environmental and socioeconomic impacts of IAS on islands and provides guidance and information on technical resources that can help minimize the effects of IAS in island ecosystems. This assessment is intended to provide a holistic perspective on island-IAS dynamics, enable biologists and social scientists to identify information gaps that warrant further research and serve as a primer for policy makers seeking to minimize the impact of IAS on island systems. Case studies have been selected to reflect the most scientifically-reliable information on the impacts of IAS on islands. Sufficient evidence has emerged to conclude that IAS are the most significant drivers of population declines and species extinctions in island ecosystems worldwide. Clearly, IAS can also have significant socioeconomic impacts directly (for example human health) and indirectly through their effects on ecosystem goods and services. These impacts are manifest at all ecological levels and affect the poorest, as well as richest, island nations. The measures needed to prevent and minimize the impacts of IAS on island ecosystems are generally known. However, many island nations and territories lack the scientific and technical information, infrastructure and human and financial resources necessary to adequately address the problems caused by IAS. Because every nation is an exporter and importer of goods and services, every nation is also a facilitator and victim of the invasion of alien species. Wealthy nations therefore need to help raise the capacity of island nations and territories to minimize the spread and impact of IAS.

The Relationship between Auditor Tenure and Audit Quality Implied by Going Concern Opinions
W. Robert Knechel, Ann Vanstraelen
2007· Auditing A Journal of Practice & Theory382doi:10.2308/aud.2007.26.1.113

The debate continues about the relationship between auditor tenure and audit quality in spite of extensive empirical evidence examining audit failures, earnings management, and the issuance of auditor's opinions. Most recent evidence suggests that long auditor tenure does not have a negative impact on audit quality. However, most of the available evidence has been accumulated based on publicly listed companies in the U.S. We examine the effect of auditor tenure on audit quality for private companies in Belgium, an environment where we believe auditor tenure is more likely to have a negative effect on audit quality. We use the likelihood of an auditor issuing a going concern opinion as an indicator of audit quality. Using a sample of stressed bankrupt companies, and stressed nonbankrupt companies, the results indicate that auditors do not become less independent over time nor do they become better at predicting bankruptcy. In balance, the evidence for tenure either increasing or decreasing quality is weak.

Gamow-Teller Matrix Elements from 0°(<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>p</mml:mi><mml:mo>,</mml:mo><mml:mi> </mml:mi><mml:mi>n</mml:mi></mml:math>) Cross Sections
C. D. Goodman, C.A. Goulding, M. B. Greenfield, J. Rapaport +4 more
1980· Physical Review Letters377doi:10.1103/physrevlett.44.1755

After simple corrections for distortion effects, 120-MeV, 0\ifmmode^\circ\else\textdegree\fi{} ($p, n$) cross sections are found to be proportional to the squares of the corresponding Fermi and Gamow-Teller matrix elements extracted from $\ensuremath{\beta}$-decay measurements. It is suggested that this proportionality can be used to extract Gamow-Teller matrix elements for transitions inaccessible to $\ensuremath{\beta}$ decay.

Ionizing-Radiation Resistance in the Desiccation-Tolerant Cyanobacterium <i>Chroococcidiopsis</i>
Daniela Billi, E. Imre Friedmann, Kurt G. Hofer, M. Grilli Caiola +1 more
2000· Applied and Environmental Microbiology370doi:10.1128/aem.66.4.1489-1492.2000

The effect of X-ray irradiation on cell survival, induction, and repair of DNA damage was studied by using 10 Chroococcidiopsis strains isolated from desert and hypersaline environments. After exposure to 2.5 kGy, the percentages of survival for the strains ranged from 80 to 35%. In the four most resistant strains, the levels of survival were reduced by 1 or 2 orders of magnitude after irradiation with 5 kGy; viable cells were recovered after exposure to 15 kGy but not after exposure to 20 kGy. The severe DNA damage evident after exposure to 2.5 kGy was repaired within 3 h, and the severe DNA damage evident after exposure to 5 kGy was repaired within 24 h. The increase in trichloroacetic acid-precipitable radioactivity in the culture supernatant after irradiation with 2.5 kGy might have been due to cell lysis and/or an excision process involved in DNA repair. The radiation resistance of Chroococcidiopsis strains may reflect the ability of these cyanobacteria to survive prolonged desiccation through efficient repair of the DNA damage that accumulates during dehydration.