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Phototrophic production of algae, either in open raceway ponds or closed systems such as PBRs or covered raceways, is increasingly considered an agricultural enterprise, albeit one not requiring soil. Particular focus on “algae as agriculture” in the last 10 years has been the result of the critical integration of traditional agricultural techniques with decades of algae cultivation knowledge to form a set of ever-growing agronomic practices for algae biomass production. There are two parts to agronomic practices: ensuring the health of the crop by providing optimum growth conditions and preventing and/or treating pests to protect the crop. The critical advancements in algae cultivation in recent years have been in crop protection, particularly the translation of integrated pest management practices from traditional agriculture. This chapter summarizes how agronomic practices can be applied to each stage of algal production which should drive future optimization.

The λ S gene encodes a holin, S105, and an antiholin, S107, which differs by its Met-Lys N-terminal extension. The model for the lysis-defective character of S107 stipulates that the additional N-terminal basic residue keeps S107 from assuming the topology of S105, which is N-out, C-in, with three transmembrane domains (TMDs). Here we show that the N terminus of S105 retains its fMet residue but that the N terminus of S107 is fully deformylated. This supports the model that in S105, TMD1 inserts into the membrane very rapidly but that in S107, it is retained in the cytoplasm. Further, it reveals that, compared to S105, S107 has two extra positively charged moieties, Lys2 and the free N-terminal amino group, to hinder its penetration into an energized membrane. Moreover, an allele, S105 ΔTMD1 , with TMD1 deleted, was found to be defective in lysis, insensitive to membrane depolarization, and dominant to the wild-type allele, indicating that the lysis-defective, antiholin character of S107 is due to the absence of TMD1 from the bilayer rather than to its ectopic localization at the inner face of the cytoplasmic membrane. Finally, the antiholin function of the deletion protein was compromised by the substitution of early-lysis missense mutations in either the deletion protein or parental S105 but restored when both S105 ΔTMD1 and holin carried the substitution.

Holins are small phage-encoded proteins that accumulate harmlessly in the cytoplasmic membrane during the infection cycle until suddenly, at an allele-specific time, triggering to form lethal lesions, or “holes.” In the phages λ and T4, the holes have been shown to be large enough to allow release of prefolded active endolysin from the cytoplasm, which results in destruction of the cell wall, followed by lysis within seconds. Here, the holes caused by S105, the λ-holin, have been captured in vivo by cryo-EM. Surprisingly, the scale of the holes is at least an order of magnitude greater than any previously described membrane channel, with an average diameter of 340 nm and some exceeding 1 μm. Most cells exhibit only one hole, randomly positioned in the membrane, irrespective of its size. Moreover, on coexpression of holin and endolysin, the degradation of the cell wall leads to spherically shaped cells and a collapsed inner membrane sac. To obtain a 3D view of the hole by cryo-electron tomography, we needed to reduce the average size of the cells significantly. By taking advantage of the coupling of bacterial cell size and growth rate, we achieved an 80% reduction in cell mass by shifting to succinate minimal medium for inductions of the S105 gene. Cryotomographic analysis of the holes revealed that they were irregular in shape and showed no evidence of membrane invagination. The unexpected scale of these holes has implications for models of holin function.

Background Epidemiological studies on posttraumatic stress disorder (PTSD) show a lifetime prevalence rate of up to 6.8%. PTSD symptoms include re-experiencing the traumatic event, avoidant behavior for the memories of the event, and hyperarousal. By 2020, psychological trauma will be among the leading causes of global disability, alongside depression and heart disease. A post-genocide study conducted in 2009 by the Ministry of Health (MoH) in Rwanda showed that PTSD prevalence was 28.5% in the adult population, and 53.9% of these cases had a comorbid depression. Providing community outreach programs at a primary care level is one of the major goals of the University of Rwanda. The Ministry of Health emphasizes the integration of mental health services into general medical care at a grass roots level. Recognizing the role of psychotrauma on physical health, the Ministry wants to implement simple but effective community mental health treatments. Methods Trauma tapping technique (TTT) is a procedure that uses touch through tapping to relieve anxiety symptoms. TTT is a nonverbal process that can be delivered at minimal cost with the potential for easy dissemination. This technique can be applied in urban or rural communities and in medical or mental health environments. Results Psychotrauma has resulted in a host of mental health issues such as PTSD, anxiety and depression. Many Rwandan families experience these conditions. TTT has been shown to be useful in anxiety, PTSD and pain control arenas. Conclusion Trauma Tapping Technique is an emerging psychological intervention that has been used to treat a variety of conditions, including exam stress and public speaking anxiety, as well as PTSD. TTT may be a feasible initial community based treatment for psychotrauma, PTSD and anxiety disorders in Rwanda. This nonverbal intervention has the potential to augment mental health care. Key words: posttraumatic stress disorder, trauma tapping therapy, nonverbal communication, genocide, mental health Rwanda

In 2006, construction workers uncovered human remains during excavation for a new development project in New York City. The remains were associated with the burial vaults of the Spring Street Presbyterian Church, which stood on the site between 1811 and 1966. The congregation was led by Reverend Dr. Samuel H. Cox from 1820 to 1825 and was influential in New York’s anti-slavery movement and as a result, was destroyed during the 1834 Anti-Abolition Riots. Like many families living in early-nineteenth century New York City, Dr. Cox and his wife were affected by high rates of childhood mortality, losing 5 of their 15 children at early ages. Despite having left the church in 1825, the Cox family continued to inter their deceased family members in the vaults beneath the Spring Street Church. Archaeological investigations at the site coupled with historic research exposed the plight of a young family that was headed by a highly visible figure, privately endured the grief associated with infant and childhood mortality.

During λ infections, the holin S105 accumulates harmlessly in the membrane until, at an allele-specific time, suddenly triggering to form irregular holes of unprecedented size (>300 nm), releasing the endolysin from the cytoplasm, resulting in lysis within seconds. Here we used a functional S105–GFP chimera and real-time deconvolution fluorescence microscopy to show that the S105–GFP fusion accumulated in a uniformly distributed fashion, until suddenly, within 1 min, it formed aggregates, or rafts, at the time of lethal triggering. Moreover, the isogenic fusion to a nonlethal S105 mutant remained uniformly distributed, whereas a fusion to an early-lysing mutant showed early triggering and early raft formation. Protein accumulation rates of the WT, early, and nonlethal alleles were identical. Fluorescence recovery after photobleaching (FRAP) revealed that the nonlethal mutant and untriggered WT hybrids were highly mobile in the membrane, whereas the WT raft was essentially immobile. Finally, an antiholin allele, S105 ΔTMD1 – mcherryfp , in the product of which the S105 sequence deleted for the first transmembrane domain was fused to mCherryFP. This hybrid retained full antiholin activity, in that it blocked lethal hole formation by the S105–GFP fusion, accumulated uniformly throughout the host membrane and prevented the S105–GFP protein from forming rafts. These findings suggest that phage lysis occurs when the holin reaches a critical concentration and nucleates to form rafts, analogous to the initiation of purple membrane formation after the induction of bacteriorhodopsin in halobacteria. This model for holin function may be relevant for processes in mammalian cells, including the release of nonenveloped viruses and apoptosis.

Summary Holins control the length of the infection cycle of tailed phages (the Caudovirales) by oligomerizing to form lethal holes in the cytoplasmic membrane at a time dictated by their primary structure. Nothing is currently known about the physical basis of their oligomerization or the structure of the oligomers formed by any known holin. Here we use electron microscopy and single-particle analysis to character- ize structures formed by the bacteriophage l holin (S105) in vitro. In non-ionic or mild zwitterionic detergents, purified S105, but not the lysis-defective variant S105A52V, forms rings of at least two size classes, the most common having inner and outer diameters of 8.5 and 23 nm respectively, and contain- ing approximately 72 S105 monomers. The height of these rings, 4 nm, closely matches the thickness of the lipid bilayer. The central channel is of unprec- edented size for channels formed by integral mem- brane proteins, consistent with the non-specific nature of holin-mediated membrane permeabiliza- tion. S105 present in detergent-solubilized rings and in inverted membrane vesicles showed similar sen- sitivities to proteolysis and cysteine-specific modifi- cation, suggesting that the rings are representative of the lethal holes formed by S105 to terminate the infection cycle and initiate lysis.

Feline immunodeficiency virus (FIV) shares with T-cell tropic strains of human immunodeficiency virus type 1 (HIV-1) the use of the chemokine receptor CXCR4 for cellular entry. In order to map the interaction of the FIV envelope surface unit (SU) with CXCR4, full-length FIV SU-Fc as well as constructs with deletions of extended loop L2, V3, V4, or V5 were produced in stable CHO cell lines. Binding studies were performed using these proteins on 3201 cells (CXCR4 hi CD134 − ), with or without the CXCR4 inhibitor AMD3100. The findings established that SU binding to CXCR4 specifically requires the V3 region of SU. Synthetic peptides spanning the V3 region as well as a panel of monoclonal antibodies (MAbs) to SU were used to further map the site of CXCR4 interaction. Both the SU V3-specific antibodies and the full-length V3 peptide potently blocked binding of SU to CXCR4 and virus entry. By using a set of nested peptides overlapping a region of SU specifically recognized by CD134-dependent neutralizing V3 MAbs, we showed that the neutralizing epitope and the region required for CXCR4 binding are within the same contiguous nine-amino-acid sequence of V3. Site-directed mutagenesis was used to reveal that serine 393 and tryptophan 394 at the predicted tip of V3 are required to facilitate entry into the target cell via CXCR4. Although the amino acid sequences are not identical between FIV and HIV, the ability of FIV to bind and utilize both feline and human CXCR4 makes the feline model an attractive venue for development of broad-based entry antagonists.

Except for filamentous phages, all phages liberate the progeny virions by lysis of the host, and almost all double-stranded DNA viruses use the holin–endolysin mode of lysis. Holins are small phage-encoded membrane proteins that permeabilize the host membrane at a programmed time. Endolysins are muralytic enzymes necessary for degrading the host peptidoglycan. The muralytic action of each phage endolysin is controlled by the holin. In some cases, the endolysin accumulates in the host cytoplasm during the infection cycle, and at a programmed time, the holin molecules trigger to form a ‘hole’ that allows the endolysin to escape across the membrane and attack the cell wall. In other cases, the endolysin is exported by the host sec system in an inactive form, and holin triggering causes activation of the enzymes as a result of the collapse of the proton-motive force. Endolysins have been found with four different enzyme activities, each of which is directed at one of the three different chemical linkages in the murein. Holins are extremely diverse and fall into at least three different topological classes, with one to three transmembrane domains. In contrast, small single-stranded nucleic acid phages have single gene responsible for lysis and no muralytic activity is elaborated. In two of these cases, the single lysis gene encodes a specific inhibitor of a host enzyme required for murein precursor biosynthesis.

Some parts of the Guideline are clearly cost-effective. Abandoning routine cultures of respiratory therapy equipment is cost-effective and should be adopted by any hospitals that have not done so already. Other practices such as the use of preoperative and postoperative instructions regarding deep breathing and incentive spirometry, and the policy of never reusing respiratory therapy equipment items that are intended for single use probably warrant further cost-benefit analysis. Finally, there is increasing evidence that changing ventilator tubing every 24 hours is not cost-effective. Changing tubing every 48 hours appears to be safe and can save hospitals substantial sums of money.

MRSA strains have become increasingly prevalent in the United States and are now an important cause of nosocomial infections in many large, medical school-affiliated hospitals. In affected institutions, from a few percent to 50% of all hospital-acquired S aureus infections are caused by MRSA strains. It has been suggested that the overall incidence of nosocomial S aureus infections may not increase in hospitals where MRSA strains have become epidemic or endemic and that MRSA strains merely replace methicillin-susceptible strains as a cause of hospital-acquired infections. Several recent studies lend support to this theory. Thompson et al [1] reported that the overall incidence of nosocomial S aureus-associated bacteremias and postoperative wound infections in a university hospital did not increase during a period when MRSA strains caused a significantly greater proportion of such infections. Similarly, Linnemann et al [2] found that the overall incidence of nosocomial S aureus-associated bacteremias did not change during a four-year period when the incidence of MRSA-associated bacteremias increased appreciably. At the University of Mississippi Medical Center, MRSA strains have been recovered from patients with increased frequency since an outbreak of MRSA infections occurred in the burn unit in June 1979 [3]. Continuing surveillance has revealed that the incidence of nosocomial MRSA infections was significantly higher in 1980-1982 than during 1979 (P = 0.002 by Mann-Whitney U test). MRSA strains accounted for 11% of nosocomial S aureus infections in 1979, 38% in 1980, 50% in 1981, 36% in 1982, and 32% in early 1983.(ABSTRACT TRUNCATED AT 250 WORDS)

During a 3 1/2-year period (January 1978 through June 1981), 245 patients in a university hospital became colonized or infected with methicillin-resistant Staphylococcus aureus . During the first 18 months, the incidence of colonization and infection was only 0.05%. After a focal outbreak of methicillin-resistant S aureus in the burn unit, acquisition of the organism by patients on other wards increased significantly. Nonburn patients acquired the organism more often during time periods when newly admitted burn patients acquired methicillin-resistant S aureus . After the burn unit was closed, acquisition of the organism among nonburn patients on adult surgical and medical services decreased significantly. A questionnaire survey of other institutions disclosed that large outbreaks of this infection occurred more frequently in hospitals with burn units. These studies suggest that the occurrence of methicillin-resistant S aureus infections in burn units may lead to increased transmission of the organism to nonburn patients and that control of the infection in such units may reduce spread of the organism to patients without burns. ( JAMA 1983;249:2803-2807)

Sir .—We would like to comment on the interesting report entitled "Unusual Multiresistant Staphylococcus aureus in a Newborn Nursery" by Trallero et al (Journal1981;135: 689-692). Nosocomial transmission of methicillin-resistant S aureus (MRSA) on pediatric wards was first reported in 1963. 1 Three outbreaks of infection among neonates due to multiresistant S aureus were reported before 1981, 2-4 and several other epidemics have been described in detail or alluded to in reports published more recently. 5,6 Multiresistant strains of S aureus have been recovered from patients at our institution since January 1978. Agar disk-diffusion susceptibility tests performed at 30 °C on isolates recovered after June 1979 revealed that these organisms were resistant to methicillin and oxacillin (100% of strains tested), erythromycin (100%), clindamycin (97%), gentamicin (96% ), cephalothin (84% ), tetracycline (64%), sulfamethoxazole and trimethoprim (51%), and cefamandole (33% ). Thirty-three representative isolates have also been tested by agar dilution methods performed at