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As opaque algorithmic systems take up a larger and larger role in shaping our lives, calls for explainability in various algorithmic systems have increased. Many moral and political philosophers have sought to vindicate these calls for explainability by developing theories on which decision-subjects—that is, individuals affected by decisions—have a moral right to the explanation of the systems that affect them. Existing theories tend to suggest that the right to explanation arises solely in virtue of facts about how decision-subjects are affected by opaque systems. But this ignores an important part of the normative landscape: sometimes, facts about a decision-maker’s rights and freedoms can make a difference to whether she owes anyone explanations of her decisions. I illustrate the point by calling attention to examples of artistic, romantic, and supererogatory altruistic decisions; in at least some cases of this sort, even highly influential decisions can legitimately be kept entirely private and opaque,

In capillary electrophoresis, it is commonly considered that even a moderately high ionic concentration in the background electrolyte (BGE) leads to high currents, resulting in Joule heating and serious peak distortion. As a new approach to overcome this problem, zwitterionic (Zwittergent-3–14) and/or non-ionic (Tween 20) surfactants have been added to BGEs containing high salt concentrations (e.g. 0.3 M NaCl) and have been shown to result in acceptable separation currents (<200 µA). In turn, these BGEs could be applied to the separation of samples containing high salt concentrations (such as undiluted seawater) without the occurrence of any significant peak broadening due to electrodispersion of the sample. For example, a BGE comprising 10 mM Zwittergent-3–14, 50 mM Tween 20, 0.3 M NaCl and 5 mM phosphate (ph 7) could be used for the determination of UV-absorbing anions in seawater, giving good peak shapes and detection limits of 0.8 µM and 0.6 µM for nitrate and bromide, respectively. The beneficial effects of the non-ionic surfactant on the separation were attributed largely to suppression of the electro-osmotic flow. On the other hand, the zwitterionic surfactant was found to be capable of the incorporation of some anions in accordance with the behaviour of these same surfactants in electrostatic ion chromatography. This incorporation resulted in a decreased conductivity of the BGE and also a change in the separation selectivity of the system.

Solid supported nucleophiles and electrophiles are employed to expedite the work-up and purification of a variety of amine alkylations acylacylations. These solid suported scavengers are particularly advantageous for the construction of non-peptide libraries in a parallel array format.

Preliminary results of a study sponsored in part by the AWWA Research Foundation outline an easy, quick, and inexpensive test for screening organic material for carcinogenic potential.

N-Cbz-(S-phenyl)-L-cysteine (3) has been prepared on a multi-kilogram scale in high yield and optical purity from the β-lactone of N-Cbz-L-serine.

A simple, sensitive and convenient ion chromatographic (IC) method with UV photometric detection using pyromellitate (l,2,4,5-benzenetetracarboxylate)-methanol-water as the eluent on a silica-based anion-exchange column was established for the simultaneous determination of common inorganic anions including HCO3−, Mg2+and Ca2+in environmental waters. The anions were detected indirectly, whilst Mg2+and Ca2+were detected directly because complexes having strong UV absorption were formed between pyromellitate and these cations. The proposed method was successfully applied to the simultaneous determination of the common anions, Mg2+and Ca2+in various river water samples.

The Collaborative Study in Coronary Artery Surgery (CASS) is a large multi-institutional study of the medical and surgical treatment of coronary artery disease. Fifteen cooperative institutions have carried out isolated coronary artery bypass grafting (CABG) on 6,258 men and 1,153 women during the period August, 1975, through May, 1980. The operative mortality in men was 1.9%, while the operative mortality for women undergoing CABG in the same institutions during the same time period was 4.5%. In an effort to explain this result, we used multivariate analysis to identify factors associated with increased mortality in women after CABG. The hypothesis that smaller physical size might be contributing to increased mortality was considered. Basic clinical and angiographic variables, size variables, including the average diameter of the grafted vessels, and gender were examined separately for patients who underwent elective and urgent and emergency procedures. Using multivariate information theory, we found that the most information regarding survival after operation is contained in basic clinical and angiographic variables. The physical size of the patient, including coronary artery diameter, helps predict operative mortality even after adjusting for differences in risk predicted by the basic variables and gender. However, the patient’s sex is not statistically significantly related to the risk of surgical death given the information available from clinical and angiographic variables and from knowledge of patient size. One possible explanation of the excess risk for coronary artery operations in women is the smaller stature and the smaller diameter of the coronary arteries in this group of patients.

Amines and acylated amines are synthesized in traditional solution phase reactions, then rapidly purified by ion exchange chromatography to yield pure products. In some instances, impurities devoid of ionizable functionality can be covalently modified prior to purification. The generic purification sequence is applicable to a variety of reactions, and is amenable to automation with commercially available equipment.

The solubilities of cuprous bromide were measured at 24.8°C in aqueous KBr and in aqueous KBr-KNO3 mixtures. The results have been analyzed to give equilibrium constanns from formation of neutral and negatively charged complexes of CuBr, and sets of virial parameters suitable for calculation of activity coefficients for the complexes.

Available data on the solubility of silver chloride in aqueous solutions of HCl, NaCl, KCl, LiCl, and NH4Cl, along with potentiometric measurements of the activity of Ag+ in aqueous NaCl-NaClO4 mixtures, have been analyzed to obtain the thermodynamic properties of the (AgCl)0, AgCl2-, AgCl32-, and AgCl43- complexes. Results obtained include the stability constants of the complexes and 25°C, the virial parameters needed to calculate the activity coefficients of the complexes and the heats of the reactions by which they are formed. These results are sued to calculate tables of recommended values for the solubility of silver chloride in the host solutions as a function of concentration from 0 to 150°C and to make a critical evaluation of the reliability of previously published data.

Methods for the detectionn of metal cations under acidic conditions, near PH 2, in capillary electrophoresis (CE) were investigatged. Conditions for direct UV detection of UV absorbing metal cations such as Cr3+, Cu2+, Fe3+, UO22+, VO2+, and VO2+ were established With aqueous HCl or HClO4 as the electroyte carrier. The speciation of vanadium(IV) and vanadium(V) at PH 2.3 by CE was achieved with direct detection at 185 nm. With the strong absorbance at 185 nm, no complexation was needed to detect the metal cations. An indirect UV detrection scheme for acidic conditions was also investigated. Several background carrier electolytes (BCES) were studied including 4‐methylbenzylamince, nicontinamide, pyridazine, guanidine, 3‐picoline, and chromium (III) to determine their effectivencess under very acidic conditions. The efect of ioni c surfactants and the nonionic surfactant, Trition X‐100, on the peak heights and N Values was also studied.

Amino Acids are cations at low PH and can be readily separated by capillarty electrophoresis provided an alkanesulfonic acid is added to the elecrolyte carrier. Formation of a Positive net charge on the bare fused‐silica surface at low PH was confirmed by measurement of an anodic electroosmotic flow. The addition of ethanesulfonic acid or octanesulfonic acid to the electrolyte carrier causes a reversal of the EOF. A mechanism is proposed in which the alkanesulfonic acid adsorbs to the positively‐charged capillary wall through electrostatci attraction. Adsorption of a second molecule of alkanesulfonate by hudrophobic attraction to the carbon chain forms a negatively‐charge coating on the capillary wall. The alkanesuflfonate also imparts selectivety to the system by participation in ionpairing interactions with the native amino acids to improve resolution. The CE separation of a mixture of the twenty common amino acids at PH 2.8 with direct absorabance detection at 185 nm resulted in 17 amino acid peals in 20 minutes with a 30 KV applied voltage. The effect of several variables was studied including electrolyte carrieres containing different alkanesulfonic acids, the influence of PH, applied voltage, and concentration of electrolyte carrier.

Methods for the preparation of the 4-diphenylphosphino derivatives of N-phenylaza-15-crown-5 and -18-crown-6 are described. The properties of these systems and the 4'-diphenylphosphino derivative of benzo-15-crown-5 have been examined by way of picrate ion extraction abilities and IR spectra of their Ni(CO)3L (L = these phosphines) complexes. All three have abilities to extract Na+ and K+ that are comparable to benzo-15-crown-5. The IR studies (νCO, A1 band) indicate that the azacrown systems have better ability than the benzocrown system to increase the electron density on the nickel center. Further, the addition of alkali metal ions, Na+ and K+, to the Ni(CO)3L solutions results in maximum shifts of ca 1.5 cm-1 for the former systems and 0.7 cm-1 for the latter system. A rationale for this observation is presented in terms of Hammett substituent constants. Finally, an X-ray structure of the phosphine oxide of the phenylaza-15-crown-5 derivative is presented. A prominent feature of the structure is that the nitrogen atom is essentially planar with the result that the crown ether ring is large and not preorganized for coordination of spherical ions.

The results of a comparison of one resin and one activated carbon in the isolation of organic compounds in water are reported.

The Collaborative Study in Coronary Artery Surgery (CASS) is a large multi-institutional study of the medical and surgical treatment of coronary artery disease (CAD). Fifteen cooperating institutes have carried out isolated coronary artery bypass grafting (CABG) on 6, 176 patients from August, 1975, through December, 1978. The operative mortality (OM) was 2.3%. In an effort to better understand the clinical and angiographic characteristics predictive of OM, we have done a multivariate discriminant analysis of variables associated with OM. Numerous clinical and angiographic variables were selected from the CASS data file and evaluated in a univariate manner for their relationship to OM. Twenty of these variables were then selected for multivariate discriminant analysis. Clinical variables of most predictive value were age, female sex, increased heart size, and congestive heart failure (CHF). Angiographic variables of importance included left ventricular wall motion abnormalities, and left main coronary disease (LMCD). The priority of operation (elective, urgent, or emergent) was also associated with OM. Six variables that contained the most predictive information were selected by discriminant analysis for a group of 6, 176 patients who had isolated bypass operations. In descending order of importance they were age, left main coronary artery stenosis ≥90%, female sex, left ventricular wall motion score, left ventricular end-diastolic pressure (LVEDP), and râles. Five other groups or subgroups of patients were also analyzed in a similar manner. There is a strong association of OM with advanced age, female sex, and variables associated with left ventricular dysfunction. The risk of OM for an individual patient may be estimated with the use of these clinical and angiographic characteristics.

Uranium(VI) can be separated quantitatively from most other metal ions by partition chromatography on a silica-gel column. The column is treated with aqueous 6Mnitric acid; after sorption of the sample, uranium(VI) is selectively and rapidly eluted by methyl isobutyl ketone. In addition to the separation of macro quantities of metal ions, the method has been used successfully for the isolation of trace amounts of metal ions from uranium(VI).

Enough experimental data on nonaqueous ion-exchange separations have been gathered to show that one is dealing with a field whose theoretical aspects are infinitely complicated. The separations can be based on several different types of chemical reactions. Apart from true ion exchange, sorption can take place by non-exchange reactions such as acid-base reactions or complex-formation, either by hydrogen bonding or by metal-ligand coordination. All these reactions can be influenced by a multitude of parameters such as solvent polarity, solvent-solute interaction by solvation or complex formation, solvent structure changes, solvent-resin matrix interaction, solvent-solvent interaction, acid-base properties of the solvent, non-exchange electrolyte invasion, and so on. Any one or several of these parameters may or may not be operative in a given case, and a given parameter can be of primary importance in one case and be only a minor contributing factor in another. In view of such complexity, one should not be surprised that the few attempts so far made to develop a theory of nonaqueous ion exchange were not too successful and could be applied only to a few rather simple cases. Even considering only one type of chemical reaction, the true ion exchange, the chances of ever arriving at a comprehensive theory appear to be pretty slim.An intriguing subject from a fundamental point of view is ion exchange in non-polar anhydrous solvents such as benzene, in which the degrees of ionic dissociation, even of strong electrolytes, are extremely low. Little fundamental work on this subject has been done so far, and still less has been done under well-defined experimental conditions. This is particularly the case with respect to the strict absence of water, which even in quite small amounts can have disproportionately great effects on ion-exchange systems in less polar solvents. A careful investigation of ion exchange in benzene or similar solvents under strictly anhydrous conditions would be an interesting subject, which could perhaps reveal the answer to the intriguing question whether ion exchange is possible only between free (dissociated) ions, or whether it can take place also between ion-pairs! This would be undoubtedly a valuable contribution to our limited knowledge on electrolytes in nonaqueous solutions.From the point of view of chemical analysis, nonaqueous ion exchange has already developed into a valuable enrichment of the analytical chemist's arsenal of separation methods. The best chances for further useful developments seem to involve separation methods based on complex-forming reactions. Many complexes form more easily in solvents less polar than water, and their ion-exchange behaviors can be influenced by modifying the solvent composition, which provides more versatility than can be expected in water. The separation of metals by anion exchange of their anionic complexes has already been well developed during the last 10 years, mostly by the use of water-containing mixed solvents. Non-exchange separations by complex formation, either by hydrogen bonding or by acid-base reaction or by ligand-exchange chromatography on resins having coordinating metal counterions, are methods particularly suitable for the use of non-polar solvents or solvents of low polarity. The macroporous resins absorb easily considerable amounts of these solvents and therefore should afford an impetus to the development of these unique possibilities of separation methods for various organic compounds.The most important and useful numerical factor for the separation of a given species is its distribution coefficient. There are many thousands of numerical values dispersed in the literature, some determined under well-defined conditions but others of only limited value because the experimental conditions were ill-defined. Quite often, indeed, one can hardly compare values from different sources because of differences in defining the coefficients. It would be most helpful for the practicing analytical chemist if reliable values were available in tables, as is the case for RF-values in chromatography or for absorption peak frequencies in spectroscopy. The following steps could help to attain this goal:1. Establish by convention a definition of the distribution coefficient and perhaps determine the conditions for its determination.2. Collect published data and catalogue those judged to be well-defined and of reasonable accuracy.

The chromatographic behavior of some 35 different metal ions has been studied using paper impregnated with phenylbenzohydroxamic acid and 2-octanone. A number of selective separations can be accomplished using eluents varying in acidity from Ph 3 to 5 or 6 molar acid.

Thirty-five experiments, each of 72 hours duration, were made in which energy and gaseous metabolism of male Rhode Island Red chickens between the ages of 4 and 133 days was measured. The conditions prevailing in the calorimeter during each experiment were: temperature, 90°F.; relative humidity, 60%; O2content, 21%; and CO2content, not exceeding 1%. The oxygen consumed during periods of 2 hours and the carbon dioxide and heat produced during periods of 8 hours were determined. In some of the experiments either casein or gelatin was fed during the twenty-third hour in order to study the thermogenic effect of these two proteins.

Storage of water samples has often produced an increase in haloforms as chlorine compounds reacted with substances in the water; the addition of ascorbic acid stabilizes the samples for eventual determination of their composition.

2′,3′-Dideoxy-3′-hydroxymethylcytidine ( 1) has been synthesized via stereoselective Rh-catalyzed hydroformylation of 2′,3′-didehydro-2′,3′-dideoxycytidine 3b. This synthesis incorporates the first successful hydroformylation of a nucleoside olefin.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A small water sample (20 to 250 ml) is passed through a small tube containing XAD-4 resin; this effectively retains the organic impurities present in the water. This tube is connected to the permanent apparatus and the sorbed organics are thermally transferred to a small Tenex pre-column while the water vapor is vented. The pre-column is closed off, pre-heated to 275–280°C, and then a valve is opened to plug-inject the vaporized sample into a gas chromatograph. The procedure works well for a variety of model organic compounds added to water and can be used for the analysis of actual water samples.

Anion-exchange resins are prepared by a two-step procedure consisting of a bromoalkylation of Rohm & Haas XAD-1 resin under mild conditions, followed by amination with trimethylamine. The five resins prepared are all of a similar low capacity and contain one, two, three, four, or six carbon atoms between the resin surface and the quaternary ammonium exchange group. The selectivity of these resins for mono- and divalent anions is evaluated. Separations are presented to demonstrate resin selectivity and to show the usefulness of these resins for practical ion chromatography. Explanations for selectivity differences on these resins are discussed.